diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -0,0 +1,19 @@
+# v0.4
+
+## Breaking
+
+- Removed interpretation-based relations: UTF-8, ISO-8601, and UUID. 
+  - Relations that depend on a specific encoding or format choice violate the library's principle of unambiguous structural conversion — there is no single canonical way to encode Text as bytes or render a UTCTime as a string.
+
+# v0.3
+
+## Breaking
+
+- `from` of `IsMany` renamed to `onfrom`.
+- New `from` function added, which is an alias to `to` with type arguments flipped.
+
+# v0.2
+
+## Breaking
+
+- Added more tests in `isManyProperties` and an `Arbitrary` constraint on its parameter `a`.
diff --git a/lawful-conversions.cabal b/lawful-conversions.cabal
--- a/lawful-conversions.cabal
+++ b/lawful-conversions.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: lawful-conversions
-version: 0.1.7
+version: 0.4.0
 synopsis: Lawful typeclasses for bidirectional conversion between types
 category: Conversion
 homepage: https://github.com/nikita-volkov/lawful-conversions
@@ -50,6 +50,8 @@
   evident what any of its instances do and it provides property-tests for you
   to validate your instances.
 
+  The laws and the concepts are based on set and category theories.
+
   = Prior work and acknowledgements
 
   This library is an offspring of the "[isomorphism-class](https://hackage.haskell.org/package/isomorphism-class)" library, expanding upon the patterns discovered there. Both libraries are maintained letting their designs compete.
@@ -83,13 +85,14 @@
   hs-source-dirs: src/library
   exposed-modules: LawfulConversions
   other-modules:
-    LawfulConversions.Classes
+    LawfulConversions.Algebra
     LawfulConversions.Optics
     LawfulConversions.Prelude
     LawfulConversions.Properties
     LawfulConversions.Proxies
     LawfulConversions.Proxies.ViaIsSome
     LawfulConversions.Relations
+    LawfulConversions.Relations.Any
     LawfulConversions.Relations.BoxedVectorAndList
     LawfulConversions.Relations.BoxedVectorAndSeq
     LawfulConversions.Relations.ByteArrayAndByteString
@@ -100,17 +103,9 @@
     LawfulConversions.Relations.ByteArrayAndWord8List
     LawfulConversions.Relations.ByteStringAndLazyByteString
     LawfulConversions.Relations.ByteStringAndLazyByteStringBuilder
-    LawfulConversions.Relations.ByteStringAndLazyText
     LawfulConversions.Relations.ByteStringAndShortByteString
-    LawfulConversions.Relations.ByteStringAndString
-    LawfulConversions.Relations.ByteStringAndText
     LawfulConversions.Relations.ByteStringAndTextArray
     LawfulConversions.Relations.ByteStringAndWord8List
-    LawfulConversions.Relations.DayAndLazyText
-    LawfulConversions.Relations.DayAndLazyTextBuilder
-    LawfulConversions.Relations.DayAndStrictTextBuilder
-    LawfulConversions.Relations.DayAndString
-    LawfulConversions.Relations.DayAndText
     LawfulConversions.Relations.Int16AndWord16
     LawfulConversions.Relations.Int32AndWord32
     LawfulConversions.Relations.Int64AndWord64
@@ -119,10 +114,7 @@
     LawfulConversions.Relations.IntMapAndMapOfInt
     LawfulConversions.Relations.IntSetAndSetOfInt
     LawfulConversions.Relations.LazyByteStringAndLazyByteStringBuilder
-    LawfulConversions.Relations.LazyByteStringAndLazyText
     LawfulConversions.Relations.LazyByteStringAndShortByteString
-    LawfulConversions.Relations.LazyByteStringAndString
-    LawfulConversions.Relations.LazyByteStringAndText
     LawfulConversions.Relations.LazyByteStringAndTextArray
     LawfulConversions.Relations.LazyByteStringAndWord8List
     LawfulConversions.Relations.LazyByteStringBuilderAndShortByteString
@@ -132,40 +124,29 @@
     LawfulConversions.Relations.LazyTextAndStrictTextBuilder
     LawfulConversions.Relations.LazyTextAndString
     LawfulConversions.Relations.LazyTextAndText
-    LawfulConversions.Relations.LazyTextAndUtcTime
-    LawfulConversions.Relations.LazyTextAndUuid
     LawfulConversions.Relations.LazyTextBuilderAndStrictTextBuilder
     LawfulConversions.Relations.LazyTextBuilderAndString
     LawfulConversions.Relations.LazyTextBuilderAndText
-    LawfulConversions.Relations.LazyTextBuilderAndUtcTime
-    LawfulConversions.Relations.LazyTextBuilderAndUuid
     LawfulConversions.Relations.ListAndSeq
     LawfulConversions.Relations.ShortByteStringAndTextArray
     LawfulConversions.Relations.ShortByteStringAndWord8List
     LawfulConversions.Relations.StrictTextBuilderAndString
     LawfulConversions.Relations.StrictTextBuilderAndText
-    LawfulConversions.Relations.StrictTextBuilderAndUtcTime
-    LawfulConversions.Relations.StrictTextBuilderAndUuid
     LawfulConversions.Relations.StringAndText
-    LawfulConversions.Relations.StringAndUtcTime
-    LawfulConversions.Relations.StringAndUuid
-    LawfulConversions.Relations.TextAndUtcTime
-    LawfulConversions.Relations.TextAndUuid
     LawfulConversions.Relations.TextArrayAndWord8List
+    LawfulConversions.Relations.Void
     LawfulConversions.TextCompat.Array
 
   build-depends:
     QuickCheck >=2.13 && <3,
     base >=4.12 && <5,
     bytestring >=0.10 && <0.13,
-    containers >=0.6 && <0.8,
+    containers >=0.6 && <0.9,
     hashable >=1 && <2,
     primitive >=0.7 && <0.10,
     profunctors >=5 && <6,
     text >=1.2 && <2.2,
-    time >=1.9 && <2,
     unordered-containers >=0.2 && <0.3,
-    uuid-types >=1.0 && <1.1,
     vector >=0.12 && <0.14,
 
 test-suite test
@@ -179,7 +160,7 @@
     bytestring >=0.11.1.0 && <0.13,
     lawful-conversions,
     primitive >=0.7 && <0.10,
-    quickcheck-instances >=0.3.32 && <0.4,
+    quickcheck-instances >=0.3.32 && <0.5,
     rebase >=1.15 && <2,
     tasty >=1.2.3 && <2,
     tasty-quickcheck >=0.11 && <0.12,
diff --git a/src/library/LawfulConversions.hs b/src/library/LawfulConversions.hs
--- a/src/library/LawfulConversions.hs
+++ b/src/library/LawfulConversions.hs
@@ -15,7 +15,7 @@
 -- > to @String :: IsSome String b => b -> String
 --
 -- > > :t from @Text
--- > from @Text :: IsMany Text b => Text -> b
+-- > from @Text :: IsSome a Text => Text -> a
 --
 -- In other words 'to' and 'from' let you explicitly specify either the source
 -- or the target type of a conversion when you need to help the type
@@ -30,13 +30,6 @@
 --     'to' a <> 'to' b <> 'to' c
 -- @
 --
--- @
--- renderNameAndHeight :: 'Text' -> 'Int' -> 'Text'
--- renderNameAndHeight name height =
---   'from' @'Data.Text.Encoding.StrictTextBuilder' $
---     "Height of " <> 'from' name <> " is " <> 'from' (show height)
--- @
---
 -- = Partial conversions
 --
 -- This library also captures the pattern of smart constructors via the 'IsSome' class, which associates a total 'to' conversion with its partial inverse 'maybeFrom'.
@@ -72,7 +65,7 @@
 -- You can also expand upon that and provide a default handling of invalid values effectively providing a lossy canonicalizing conversion ([Surjection](https://en.wikipedia.org/wiki/Surjective_function)):
 --
 -- > instance IsMany Double Percent where
--- >   from double =
+-- >   onfrom double =
 -- >     if double < 0
 -- >       then Percent 0
 -- >       else if double > 1
@@ -88,6 +81,10 @@
     Is,
 
     -- * Combinators
+    from,
+    maybeTo,
+    tryFrom,
+    tryTo,
     onto,
 
     -- * Optics
@@ -105,7 +102,7 @@
   )
 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Optics
 import LawfulConversions.Properties
 import LawfulConversions.Proxies
diff --git a/src/library/LawfulConversions/Algebra.hs b/src/library/LawfulConversions/Algebra.hs
new file mode 100644
--- /dev/null
+++ b/src/library/LawfulConversions/Algebra.hs
@@ -0,0 +1,225 @@
+module LawfulConversions.Algebra where
+
+import LawfulConversions.Prelude
+
+-- |
+-- Evidence that all values of type @b@ form a subset of all values of type @a@.
+--
+-- [From Wikipedia](https://en.wikipedia.org/wiki/Subset):
+--
+-- In mathematics, a set A is a subset of a set B if all elements of A are also elements of B; B is then a superset of A. It is possible for A and B to be equal; if they are unequal, then A is a proper subset of B. The relationship of one set being a subset of another is called inclusion (or sometimes containment). A is a subset of B may also be expressed as B includes (or contains) A or A is included (or contained) in B. A k-subset is a subset with k elements.
+--
+-- === Laws
+--
+-- ==== 'to' is [injective](https://en.wikipedia.org/wiki/Injective_function)
+--
+-- For every two values of type @b@ that are not equal converting with 'to' produces values that are not equal as well:
+--
+-- > \(b1, b2) -> b1 == b2 || to @a b1 /= to @a b2
+--
+-- ==== 'maybeFrom' is a [partial inverse](https://en.wikipedia.org/wiki/Inverse_function#Partial_inverses) of 'to'
+--
+-- For all values of @b@ converting to @a@ and then attempting to convert back to @b@ always succeeds and produces a value that is equal to the original:
+--
+-- > \b -> maybeFrom (to @a b) == Just b
+--
+-- ==== 'maybeFrom' characterizes the image of 'to'
+--
+-- 'maybeFrom' succeeds exactly on values that are in the image of 'to':
+--
+-- > \a b -> maybeFrom a == Just b ==> to b == a
+--
+-- ==== Mathematical foundation
+--
+-- These laws establish that type @b@ forms a subset of type @a@ in the mathematical sense.
+-- The 'to' function provides the canonical injection, while 'maybeFrom' recognizes which values of @a@
+-- correspond to values from the subset @b@.
+--
+-- === Testing
+--
+-- For testing whether your instances conform to these laws use 'LawfulConversions.isSomeProperties'.
+class IsSome a b where
+  -- |
+  -- Convert a value of a subset type to a superset type.
+  to :: b -> a
+
+  -- |
+  -- [Partial inverse](https://en.wikipedia.org/wiki/Inverse_function#Partial_inverses) of 'to'.
+  maybeFrom :: a -> Maybe b
+
+  -- |
+  -- Requires the presence of 'IsSome' in reverse direction.
+  default maybeFrom :: (IsSome b a) => a -> Maybe b
+  maybeFrom = Just . to
+
+-- |
+-- Convert a value of a subset type to a superset type, specifying the source subset type first.
+--
+-- Alias to 'to' with the only difference in the argument order.
+--
+-- E.g.,
+--
+-- > fromText = from @Text
+from :: forall b a. (IsSome a b) => b -> a
+from = to
+
+-- |
+-- Try to convert a value of a superset type to a subset type specifying the target subset type first.
+--
+-- Alias to 'maybeFrom' with the only difference in the argument order.
+--
+-- Particularly useful in combination with the @TypeApplications@ extension,
+-- where it allows to specify the target type, e.g.:
+--
+-- > maybeToInt16 :: Int32 -> Maybe Int16
+-- > maybeToInt16 = maybeTo @Int16
+--
+-- > percent = maybeTo @Percent someDouble
+maybeTo :: forall b a. (IsSome a b) => a -> Maybe b
+maybeTo = maybeFrom
+
+-- |
+-- Like 'maybeFrom', but returns an 'Either' with the provided error on failure.
+--
+-- Useful for raising custom errors when conversion fails.
+tryFrom :: (IsSome a b) => e -> a -> Either e b
+tryFrom err a =
+  case maybeFrom a of
+    Just b -> Right b
+    Nothing -> Left err
+
+-- |
+-- Alias to 'tryFrom', which lets you specify the target type of the conversion first using @TypeApplications@.
+tryTo :: forall b a e. (IsSome a b) => e -> a -> Either e b
+tryTo = tryFrom
+
+-- |
+-- Lossy or canonicalizing conversion.
+-- Captures mappings from multiple alternative inputs into one output.
+--
+-- E.g.,
+--
+-- - `ByteString` can be decoded into `Text` with UTF-8 leniently, replacing the invalid chars with a default char.
+--
+-- - `String` has a wider range of supported chars than `Text`, so some chars get replaced too.
+--
+-- === Laws
+--
+-- ==== 'onfrom' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'to'
+--
+-- > \b -> b == onfrom (to @a b)
+--
+-- ==== 'onfrom' is [surjective](https://en.wikipedia.org/wiki/Surjective_function)
+--
+-- Every value of type @b@ can be obtained by applying 'onfrom' to some value of type @a@:
+--
+-- > \b -> exists a. onfrom @a @b a == b
+--
+-- Note: This property cannot be directly tested with QuickCheck as it requires existential quantification.
+--
+-- ==== Law hierarchy
+--
+-- 'IsMany' extends 'IsSome', so all laws from 'IsSome' also apply here.
+-- The combination ensures that 'onfrom' provides a canonical (possibly lossy) conversion from @a@ to @b@,
+-- while 'to' provides the lossless injection from @b@ to @a@.
+--
+-- === Testing
+--
+-- For testing whether your instances conform to these laws use 'LawfulConversions.isManyProperties'.
+class (IsSome a b) => IsMany a b where
+  -- |
+  -- Possibly lossy inverse of 'to'.
+  -- [Surjection](https://en.wikipedia.org/wiki/Surjective_function) from @a@ to @b@.
+  --
+  -- Particularly useful in combination with the @TypeApplications@ extension,
+  -- where it allows to specify the input type, e.g.:
+  --
+  -- > fromString :: IsMany String b => String -> b
+  -- > fromString = onfrom @String
+  --
+  -- If you want to specify the output type instead, use 'onto'.
+  onfrom :: a -> b
+
+  -- |
+  -- Requires the presence of 'IsSome' in reverse direction.
+  default onfrom :: (IsSome b a) => a -> b
+  onfrom = to
+
+-- |
+-- Alias to 'onfrom', which lets you specify the target type of the conversion first using @TypeApplications@.
+--
+-- In mathematics @onto@ is another name for [Surjective function](https://en.wikipedia.org/wiki/Surjective_function).
+--
+-- E.g.,
+--
+-- > lenientDecodeUtf8 = onto @Text
+--
+-- @
+-- combineTexts :: 'Text' -> 'ByteString' -> 'Int' -> 'Text'
+-- combineTexts name email height =
+--   'from' @'Data.Text.Encoding.StrictTextBuilder' $
+--     "Height of " <> 'to' name <> " is " <> 'onto' (show height) <> " and email is " <> 'onto' email
+-- @
+onto :: forall b a. (IsMany a b) => a -> b
+onto = onfrom
+
+-- | Bidirectional conversion between two types with no loss of information.
+--
+-- The bidirectionality is encoded via a recursive dependency with arguments
+-- flipped.
+--
+-- You can read the signature @Is a b@ as \"/B/ is /A/\".
+--
+-- === Laws
+--
+-- ==== 'from' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'to'
+--
+-- For all values of /b/ converting from /b/ to /a/ and then converting from /a/ to /b/ produces the original value:
+--
+-- > \b -> b == from @a (to @a b)
+--
+-- ==== 'to' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'from'
+--
+-- For all values of /a/ converting from /a/ to /b/ and then converting from /b/ to /a/ produces the original value:
+--
+-- > \a -> a == to @a (from @a @b a)
+--
+-- ==== Mathematical relationship
+--
+-- These two laws together establish that 'to' and 'from' form a true [isomorphism](https://en.wikipedia.org/wiki/Isomorphism) between types @a@ and @b@.
+-- Note that 'from' is implemented as 'to' from the reverse 'Is' instance, ensuring the symmetry required for isomorphisms.
+--
+-- ==== 'from' equals 'onfrom'
+--
+-- For isomorphic types, both ways of converting should be equivalent:
+--
+-- > \a -> from @a @b a == onfrom @a @b a
+--
+-- === Testing
+--
+-- For testing whether your instances conform to these laws use 'LawfulConversions.isProperties'.
+--
+-- === Instance Definition
+--
+-- For each pair of isomorphic types (/A/ and /B/) the compiler will require you to define six instances, namely: @Is A B@ and @Is B A@, @IsMany A B@ and @IsMany B A@, @IsSome A B@ and @IsSome B A@.
+--
+-- Instances of @Is@ do not define any functions and serve merely as a statement that the laws are satisfied.
+--
+-- ==== Example: Lazy Text and Text
+--
+-- @
+-- instance IsSome "Data.Text.Lazy.LazyText" "Data.Text.Text" where
+--   to = LazyText.'Data.Text.Lazy.fromStrict'
+--
+-- instance IsSome "Data.Text.Text" "Data.Text.Lazy.LazyText" where
+--   to = LazyText.'Data.Text.Lazy.toStrict'
+--
+-- instance IsMany "Data.Text.Lazy.LazyText" "Data.Text.Text"
+--
+-- instance IsMany "Data.Text.Text" "Data.Text.Lazy.LazyText"
+--
+-- instance Is "Data.Text.Lazy.LazyText" "Data.Text.Text"
+--
+-- instance Is "Data.Text.Text" "Data.Text.Lazy.LazyText"
+-- @
+class (IsMany a b, Is b a) => Is a b
diff --git a/src/library/LawfulConversions/Classes.hs b/src/library/LawfulConversions/Classes.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Classes.hs
+++ /dev/null
@@ -1,158 +0,0 @@
-module LawfulConversions.Classes where
-
-import LawfulConversions.Prelude
-
--- |
--- Evidence that all values of type @b@ form a subset of all values of type @a@.
---
--- [From Wikipedia](https://en.wikipedia.org/wiki/Subset):
---
--- In mathematics, a set A is a subset of a set B if all elements of A are also elements of B; B is then a superset of A. It is possible for A and B to be equal; if they are unequal, then A is a proper subset of B. The relationship of one set being a subset of another is called inclusion (or sometimes containment). A is a subset of B may also be expressed as B includes (or contains) A or A is included (or contained) in B. A k-subset is a subset with k elements.
---
--- === Laws
---
--- ==== 'to' is [injective](https://en.wikipedia.org/wiki/Injective_function)
---
--- For every two values of type @b@ that are not equal converting with 'to' produces values that are not equal as well:
---
--- > \(b1, b2) -> b1 == b2 || to @a b1 /= to @a b2
---
--- ==== 'maybeFrom' is a [partial inverse](https://en.wikipedia.org/wiki/Inverse_function#Partial_inverses) of 'to'
---
--- For all values of @b@ converting to @a@ and then attempting to convert back to @b@ always succeeds and produces a value that is equal to the original:
---
--- > \b -> maybeFrom (to @a b) == Just b
---
--- === Testing
---
--- For testing whether your instances conform to these laws use 'LawfulConversions.isSomeProperties'.
-class IsSome a b where
-  -- |
-  -- Convert a value of a subset type to a superset type.
-  to :: b -> a
-
-  -- |
-  -- [Partial inverse](https://en.wikipedia.org/wiki/Inverse_function#Partial_inverses) of 'to'.
-  maybeFrom :: a -> Maybe b
-
-  -- |
-  -- Requires the presence of 'IsSome' in reverse direction.
-  default maybeFrom :: (IsSome b a) => a -> Maybe b
-  maybeFrom = Just . to
-
--- | Every type is isomorphic to itself.
-instance IsSome a a where
-  to = id
-  maybeFrom = Just . id
-
--- | The empty set has no elements, and therefore is vacuously a subset of any set.
-instance IsSome a Void where
-  to = absurd
-  maybeFrom = const Nothing
-
--- |
--- Lossy or canonicalizing conversion.
--- Captures mappings from multiple alternative inputs into one output.
---
--- E.g.,
---
--- - `ByteString` can be decoded into `Text` with UTF-8 leniently, replacing the invalid chars with a default char.
---
--- - `String` has a wider range of supported chars than `Text`, so some chars get replaced too.
---
--- === Laws
---
--- ==== 'from' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'to'
---
--- > \b -> b == from (to @a b)
---
--- === Testing
---
--- For testing whether your instances conform to these laws use 'LawfulConversions.isManyProperties'.
-class (IsSome a b) => IsMany a b where
-  -- |
-  -- Possibly lossy inverse of 'to'.
-  -- [Surjection](https://en.wikipedia.org/wiki/Surjective_function) from @a@ to @b@.
-  --
-  -- Particularly useful in combination with the @TypeApplications@ extension,
-  -- where it allows to specify the input type, e.g.:
-  --
-  -- > fromText :: IsMany Text b => Text -> b
-  -- > fromText = from @Text
-  --
-  -- The first type application of the 'to' function on the other hand specifies
-  -- the output data type.
-  --
-  -- If you want to specify the output type instead, use 'onto'.
-  from :: a -> b
-
-  -- |
-  -- Requires the presence of 'IsSome' in reverse direction.
-  default from :: (IsSome b a) => a -> b
-  from = to
-
--- |
--- Alias to 'from', which lets you specify the target type of the conversion first using @TypeApplications@.
---
--- In mathematics @onto@ is another name for [Surjective function](https://en.wikipedia.org/wiki/Surjective_function).
---
--- E.g.,
---
--- > lenientDecodeUtf8 = onto @Text
-onto :: forall b a. (IsMany a b) => a -> b
-onto = from
-
-instance IsMany a a
-
--- | Bidirectional conversion between two types with no loss of information.
---
--- The bidirectionality is encoded via a recursive dependency with arguments
--- flipped.
---
--- You can read the signature @Is a b@ as \"/B/ is /A/\".
---
--- === Laws
---
--- ==== 'from' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'to'
---
--- For all values of /b/ converting from /b/ to /a/ and then converting from /a/ to /b/ produces the original value:
---
--- > \b -> b == from (to @a b)
---
--- ==== 'to' is an [inverse](https://en.wikipedia.org/wiki/Inverse_function) of 'from'
---
--- For all values of /a/ converting from /a/ to /b/ and then converting from /b/ to /a/ produces the original value:
---
--- > \a -> a == to (from @a @b a)
---
--- === Testing
---
--- For testing whether your instances conform to these laws use 'LawfulConversions.isProperties'.
---
--- === Instance Definition
---
--- For each pair of isomorphic types (/A/ and /B/) the compiler will require you to define six instances, namely: @Is A B@ and @Is B A@, @IsMany A B@ and @IsMany B A@, @IsSome A B@ and @IsSome B A@.
---
--- Instances of @Is@ do not define any functions and serve merely as a statement that the laws are satisfied.
---
--- ==== Example: Lazy Text and Text
---
--- @
--- instance IsSome "Data.Text.Lazy.LazyText" "Data.Text.Text" where
---   to = LazyText.'Data.Text.Lazy.fromStrict'
---
--- instance IsSome "Data.Text.Text" "Data.Text.Lazy.LazyText" where
---   to = LazyText.'Data.Text.Lazy.toStrict'
---
--- instance IsMany "Data.Text.Lazy.LazyText" "Data.Text.Text"
---
--- instance IsMany "Data.Text.Text" "Data.Text.Lazy.LazyText"
---
--- instance Is "Data.Text.Lazy.LazyText" "Data.Text.Text"
---
--- instance Is "Data.Text.Text" "Data.Text.Lazy.LazyText"
--- @
-class (IsMany a b, Is b a) => Is a b
-
--- | Any type is isomorphic to itself.
-instance Is a a
diff --git a/src/library/LawfulConversions/Optics.hs b/src/library/LawfulConversions/Optics.hs
--- a/src/library/LawfulConversions/Optics.hs
+++ b/src/library/LawfulConversions/Optics.hs
@@ -1,7 +1,7 @@
 module LawfulConversions.Optics where
 
 import Data.Profunctor
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 -- | Van-Laarhoven-style Prism, compatible with libraries like \"lens\" and \"optics\".
@@ -14,7 +14,7 @@
 
 -- | Van-Laarhoven-style Isomorphism, compatible with libraries like \"lens\" and \"optics\".
 isManyIso :: (IsMany a b, Profunctor p, Functor f) => p b (f b) -> p a (f a)
-isManyIso = dimap from (fmap to)
+isManyIso = dimap onfrom (fmap to)
 
 -- | Van-Laarhoven-style Isomorphism, compatible with libraries like \"lens\" and \"optics\".
 isIso :: (Is a b, Profunctor p, Functor f) => p b (f b) -> p a (f a)
diff --git a/src/library/LawfulConversions/Prelude.hs b/src/library/LawfulConversions/Prelude.hs
--- a/src/library/LawfulConversions/Prelude.hs
+++ b/src/library/LawfulConversions/Prelude.hs
@@ -55,7 +55,6 @@
 import Data.Text as Exports (Text)
 import Data.Traversable as Exports
 import Data.Tuple as Exports
-import Data.UUID.Types as Exports (UUID)
 import Data.Vector as Exports (Vector)
 import Data.Version as Exports
 import Data.Void as Exports
diff --git a/src/library/LawfulConversions/Properties.hs b/src/library/LawfulConversions/Properties.hs
--- a/src/library/LawfulConversions/Properties.hs
+++ b/src/library/LawfulConversions/Properties.hs
@@ -5,7 +5,7 @@
   )
 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import Test.QuickCheck
 
@@ -22,19 +22,27 @@
 -- >       (uncurry prop)
 -- >       (isSomeProperties @Int32 @Int16 Proxy Proxy)
 isSomeProperties ::
-  (IsSome a b, Eq a, Eq b, Show a, Show b, Arbitrary b) =>
+  forall a b.
+  (IsSome a b, Eq a, Eq b, Show a, Show b, Arbitrary a, Arbitrary b) =>
   Proxy a ->
   Proxy b ->
   [(String, Property)]
 isSomeProperties aProxy bProxy =
   [ ( "'to' is injective",
-      property \a b ->
-        a /= b ==>
-          to' a =/= to' b
+      property \b1 b2 ->
+        if b1 == b2
+          then property True
+          else to' b1 =/= to' b2
     ),
     ( "'maybeFrom' is a partial inverse of 'to'",
+      property \b ->
+        maybeFrom' (to' b) === Just b
+    ),
+    ( "'maybeFrom' characterizes the image of 'to'",
       property \a ->
-        maybeFrom' (to' a) === Just a
+        case maybeFrom' a of
+          Just b -> to' b === a
+          Nothing -> property True
     )
   ]
   where
@@ -54,18 +62,30 @@
 -- >       (uncurry prop)
 -- >       (isManyProperties @String @Text Proxy Proxy)
 isManyProperties ::
-  (IsMany a b, Eq a, Eq b, Show a, Show b, Arbitrary b) =>
+  forall a b.
+  (IsMany a b, Eq a, Eq b, Show a, Show b, Arbitrary a, Arbitrary b) =>
   Proxy a ->
   Proxy b ->
   [(String, Property)]
 isManyProperties aProxy bProxy =
-  ( "'from' is an inverse of 'to'",
-    property \b -> b === from' (to' b)
-  )
-    : isSomeProperties aProxy bProxy
+  [ ( "'onfrom' is an inverse of 'to'",
+      property \b -> b === onfrom' (to' b)
+    ),
+    ( "'onfrom' is consistent with 'maybeFrom'",
+      property \(b :: b) ->
+        let a = to @a b
+         in maybeFrom (to @a b) === Just (onfrom @a @b a)
+    ),
+    ( "'to' after 'onfrom' always succeeds with 'maybeFrom'",
+      property \a ->
+        let b = onfrom' a
+         in maybeFrom (to' b) === Just b
+    )
+  ]
+    <> isSomeProperties aProxy bProxy
   where
     to' = as aProxy . to . as bProxy
-    from' = as bProxy . from . as aProxy
+    onfrom' = as bProxy . onfrom . as aProxy
 
 -- |
 -- Properties testing whether an instance satisfies the laws of 'Is'.
@@ -85,10 +105,15 @@
   Proxy b ->
   [(String, Property)]
 isProperties aProxy bProxy =
-  ( "'to' is an inverse of 'from'",
-    property \b -> b === to' (from' b)
-  )
-    : isManyProperties aProxy bProxy
+  [ ( "'to' is an inverse of 'from'",
+      property \b -> b === to' (from' b)
+    ),
+    ( "'from' equals 'onfrom'",
+      property \a -> from' a === onfrom' a
+    )
+  ]
+    <> isManyProperties aProxy bProxy
   where
     to' = as aProxy . to . as bProxy
     from' = as bProxy . from . as aProxy
+    onfrom' = as bProxy . onfrom . as aProxy
diff --git a/src/library/LawfulConversions/Proxies/ViaIsSome.hs b/src/library/LawfulConversions/Proxies/ViaIsSome.hs
--- a/src/library/LawfulConversions/Proxies/ViaIsSome.hs
+++ b/src/library/LawfulConversions/Proxies/ViaIsSome.hs
@@ -1,6 +1,6 @@
 module LawfulConversions.Proxies.ViaIsSome where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified Test.QuickCheck as QuickCheck
 
diff --git a/src/library/LawfulConversions/Relations.hs b/src/library/LawfulConversions/Relations.hs
--- a/src/library/LawfulConversions/Relations.hs
+++ b/src/library/LawfulConversions/Relations.hs
@@ -1,5 +1,6 @@
 module LawfulConversions.Relations () where
 
+import LawfulConversions.Relations.Any ()
 import LawfulConversions.Relations.BoxedVectorAndList ()
 import LawfulConversions.Relations.BoxedVectorAndSeq ()
 import LawfulConversions.Relations.ByteArrayAndByteString ()
@@ -10,17 +11,9 @@
 import LawfulConversions.Relations.ByteArrayAndWord8List ()
 import LawfulConversions.Relations.ByteStringAndLazyByteString ()
 import LawfulConversions.Relations.ByteStringAndLazyByteStringBuilder ()
-import LawfulConversions.Relations.ByteStringAndLazyText ()
 import LawfulConversions.Relations.ByteStringAndShortByteString ()
-import LawfulConversions.Relations.ByteStringAndString ()
-import LawfulConversions.Relations.ByteStringAndText ()
 import LawfulConversions.Relations.ByteStringAndTextArray ()
 import LawfulConversions.Relations.ByteStringAndWord8List ()
-import LawfulConversions.Relations.DayAndLazyText ()
-import LawfulConversions.Relations.DayAndLazyTextBuilder ()
-import LawfulConversions.Relations.DayAndStrictTextBuilder ()
-import LawfulConversions.Relations.DayAndString ()
-import LawfulConversions.Relations.DayAndText ()
 import LawfulConversions.Relations.Int16AndWord16 ()
 import LawfulConversions.Relations.Int32AndWord32 ()
 import LawfulConversions.Relations.Int64AndWord64 ()
@@ -29,10 +22,7 @@
 import LawfulConversions.Relations.IntMapAndMapOfInt ()
 import LawfulConversions.Relations.IntSetAndSetOfInt ()
 import LawfulConversions.Relations.LazyByteStringAndLazyByteStringBuilder ()
-import LawfulConversions.Relations.LazyByteStringAndLazyText ()
 import LawfulConversions.Relations.LazyByteStringAndShortByteString ()
-import LawfulConversions.Relations.LazyByteStringAndString ()
-import LawfulConversions.Relations.LazyByteStringAndText ()
 import LawfulConversions.Relations.LazyByteStringAndTextArray ()
 import LawfulConversions.Relations.LazyByteStringAndWord8List ()
 import LawfulConversions.Relations.LazyByteStringBuilderAndShortByteString ()
@@ -42,23 +32,14 @@
 import LawfulConversions.Relations.LazyTextAndStrictTextBuilder ()
 import LawfulConversions.Relations.LazyTextAndString ()
 import LawfulConversions.Relations.LazyTextAndText ()
-import LawfulConversions.Relations.LazyTextAndUtcTime ()
-import LawfulConversions.Relations.LazyTextAndUuid ()
 import LawfulConversions.Relations.LazyTextBuilderAndStrictTextBuilder ()
 import LawfulConversions.Relations.LazyTextBuilderAndString ()
 import LawfulConversions.Relations.LazyTextBuilderAndText ()
-import LawfulConversions.Relations.LazyTextBuilderAndUtcTime ()
-import LawfulConversions.Relations.LazyTextBuilderAndUuid ()
 import LawfulConversions.Relations.ListAndSeq ()
 import LawfulConversions.Relations.ShortByteStringAndTextArray ()
 import LawfulConversions.Relations.ShortByteStringAndWord8List ()
 import LawfulConversions.Relations.StrictTextBuilderAndString ()
 import LawfulConversions.Relations.StrictTextBuilderAndText ()
-import LawfulConversions.Relations.StrictTextBuilderAndUtcTime ()
-import LawfulConversions.Relations.StrictTextBuilderAndUuid ()
 import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-import LawfulConversions.Relations.StringAndUuid ()
-import LawfulConversions.Relations.TextAndUtcTime ()
-import LawfulConversions.Relations.TextAndUuid ()
 import LawfulConversions.Relations.TextArrayAndWord8List ()
+import LawfulConversions.Relations.Void ()
diff --git a/src/library/LawfulConversions/Relations/Any.hs b/src/library/LawfulConversions/Relations/Any.hs
new file mode 100644
--- /dev/null
+++ b/src/library/LawfulConversions/Relations/Any.hs
@@ -0,0 +1,17 @@
+{-# OPTIONS_GHC -Wno-orphans #-}
+
+module LawfulConversions.Relations.Any where
+
+import LawfulConversions.Algebra
+import LawfulConversions.Prelude
+
+-- | Any type is isomorphic to itself.
+instance IsSome a a where
+  to = id
+  maybeFrom = Just . id
+
+-- | Any type is isomorphic to itself.
+instance IsMany a a
+
+-- | Any type is isomorphic to itself.
+instance Is a a
diff --git a/src/library/LawfulConversions/Relations/BoxedVectorAndList.hs b/src/library/LawfulConversions/Relations/BoxedVectorAndList.hs
--- a/src/library/LawfulConversions/Relations/BoxedVectorAndList.hs
+++ b/src/library/LawfulConversions/Relations/BoxedVectorAndList.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.BoxedVectorAndList where
 
 import qualified Data.Vector
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome (Vector a) [a] where
diff --git a/src/library/LawfulConversions/Relations/BoxedVectorAndSeq.hs b/src/library/LawfulConversions/Relations/BoxedVectorAndSeq.hs
--- a/src/library/LawfulConversions/Relations/BoxedVectorAndSeq.hs
+++ b/src/library/LawfulConversions/Relations/BoxedVectorAndSeq.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.Sequence
 import qualified Data.Vector
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome (Vector a) (Seq a) where
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndByteString.hs b/src/library/LawfulConversions/Relations/ByteArrayAndByteString.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndByteString.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndByteString.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.ByteString.Short
 import qualified Data.Primitive.ByteArray
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.ByteArrayAndShortByteString ()
 import LawfulConversions.Relations.ByteStringAndShortByteString ()
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteString.hs b/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteString.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteString.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteString.hs
@@ -5,7 +5,7 @@
 import qualified Data.ByteString.Lazy
 import qualified Data.ByteString.Short
 import qualified Data.Primitive.ByteArray
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.ByteArrayAndShortByteString ()
 import LawfulConversions.Relations.LazyByteStringAndShortByteString ()
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteStringBuilder.hs b/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteStringBuilder.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteStringBuilder.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndLazyByteStringBuilder.hs
@@ -5,7 +5,7 @@
 import qualified Data.ByteString.Builder
 import qualified Data.ByteString.Short
 import qualified Data.Primitive.ByteArray
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.ByteArrayAndShortByteString ()
 import LawfulConversions.Relations.LazyByteStringBuilderAndShortByteString ()
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndShortByteString.hs b/src/library/LawfulConversions/Relations/ByteArrayAndShortByteString.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndShortByteString.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndShortByteString.hs
@@ -5,7 +5,7 @@
 import qualified Data.ByteString.Short
 import qualified Data.ByteString.Short.Internal
 import qualified Data.Primitive.ByteArray
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 
 instance IsSome Data.ByteString.Short.ShortByteString Data.Primitive.ByteArray.ByteArray where
   to (Data.Primitive.ByteArray.ByteArray array) =
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndTextArray.hs b/src/library/LawfulConversions/Relations/ByteArrayAndTextArray.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndTextArray.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndTextArray.hs
@@ -7,7 +7,7 @@
 
 import qualified Data.Primitive.ByteArray
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/ByteArrayAndWord8List.hs b/src/library/LawfulConversions/Relations/ByteArrayAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/ByteArrayAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/ByteArrayAndWord8List.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ByteArrayAndWord8List where
 
 import qualified Data.Primitive.ByteArray
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.ByteArrayAndShortByteString ()
 
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndLazyByteString.hs b/src/library/LawfulConversions/Relations/ByteStringAndLazyByteString.hs
--- a/src/library/LawfulConversions/Relations/ByteStringAndLazyByteString.hs
+++ b/src/library/LawfulConversions/Relations/ByteStringAndLazyByteString.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ByteStringAndLazyByteString where
 
 import qualified Data.ByteString.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome ByteString Data.ByteString.Lazy.ByteString where
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndLazyByteStringBuilder.hs b/src/library/LawfulConversions/Relations/ByteStringAndLazyByteStringBuilder.hs
--- a/src/library/LawfulConversions/Relations/ByteStringAndLazyByteStringBuilder.hs
+++ b/src/library/LawfulConversions/Relations/ByteStringAndLazyByteStringBuilder.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.ByteString.Builder
 import qualified Data.ByteString.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome ByteString Data.ByteString.Builder.Builder where
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndLazyText.hs b/src/library/LawfulConversions/Relations/ByteStringAndLazyText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/ByteStringAndLazyText.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.ByteStringAndLazyText where
-
-import qualified Data.ByteString.Lazy
-import qualified Data.Text.Encoding.Error
-import qualified Data.Text.Lazy
-import qualified Data.Text.Lazy.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome ByteString Data.Text.Lazy.Text where
-  to = Data.ByteString.Lazy.toStrict . Data.Text.Lazy.Encoding.encodeUtf8
-  maybeFrom = either (const Nothing) Just . Data.Text.Lazy.Encoding.decodeUtf8' . Data.ByteString.Lazy.fromStrict
-
--- | Lenient UTF-8 decoding.
-instance IsMany ByteString Data.Text.Lazy.Text where
-  from = Data.Text.Lazy.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode . Data.ByteString.Lazy.fromStrict
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndShortByteString.hs b/src/library/LawfulConversions/Relations/ByteStringAndShortByteString.hs
--- a/src/library/LawfulConversions/Relations/ByteStringAndShortByteString.hs
+++ b/src/library/LawfulConversions/Relations/ByteStringAndShortByteString.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ByteStringAndShortByteString where
 
 import qualified Data.ByteString.Short
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome ByteString Data.ByteString.Short.ShortByteString where
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndString.hs b/src/library/LawfulConversions/Relations/ByteStringAndString.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/ByteStringAndString.hs
+++ /dev/null
@@ -1,18 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.ByteStringAndString where
-
-import qualified Data.Text
-import qualified Data.Text.Encoding
-import qualified Data.Text.Encoding.Error
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome ByteString String where
-  to = Data.Text.Encoding.encodeUtf8 . Data.Text.pack
-  maybeFrom = either (const Nothing) (Just . Data.Text.unpack) . Data.Text.Encoding.decodeUtf8'
-
--- | Lenient UTF-8 decoding.
-instance IsMany ByteString String where
-  from = Data.Text.unpack . Data.Text.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndText.hs b/src/library/LawfulConversions/Relations/ByteStringAndText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/ByteStringAndText.hs
+++ /dev/null
@@ -1,17 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.ByteStringAndText where
-
-import qualified Data.Text.Encoding
-import qualified Data.Text.Encoding.Error
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome ByteString Text where
-  to = Data.Text.Encoding.encodeUtf8
-  maybeFrom = either (const Nothing) Just . Data.Text.Encoding.decodeUtf8'
-
--- | Lenient UTF-8 decoding.
-instance IsMany ByteString Text where
-  from = Data.Text.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndTextArray.hs b/src/library/LawfulConversions/Relations/ByteStringAndTextArray.hs
--- a/src/library/LawfulConversions/Relations/ByteStringAndTextArray.hs
+++ b/src/library/LawfulConversions/Relations/ByteStringAndTextArray.hs
@@ -7,7 +7,7 @@
 
 import qualified Data.ByteString.Short
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/ByteStringAndWord8List.hs b/src/library/LawfulConversions/Relations/ByteStringAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/ByteStringAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/ByteStringAndWord8List.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ByteStringAndWord8List where
 
 import qualified Data.ByteString
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome ByteString [Word8] where
diff --git a/src/library/LawfulConversions/Relations/DayAndLazyText.hs b/src/library/LawfulConversions/Relations/DayAndLazyText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/DayAndLazyText.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.DayAndLazyText where
-
-import qualified Data.Text.Lazy
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.DayAndString ()
-import LawfulConversions.Relations.LazyTextAndString ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Lazy.Text Day where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/DayAndLazyTextBuilder.hs b/src/library/LawfulConversions/Relations/DayAndLazyTextBuilder.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/DayAndLazyTextBuilder.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.DayAndLazyTextBuilder where
-
-import qualified Data.Text.Lazy.Builder
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.DayAndString ()
-import LawfulConversions.Relations.LazyTextBuilderAndString ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Lazy.Builder.Builder Day where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/DayAndStrictTextBuilder.hs b/src/library/LawfulConversions/Relations/DayAndStrictTextBuilder.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/DayAndStrictTextBuilder.hs
+++ /dev/null
@@ -1,36 +0,0 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.DayAndStrictTextBuilder where
-
-#if MIN_VERSION_text(2,1,2)
-
-import qualified Data.Text.Encoding
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.StrictTextBuilderAndString ()
-import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.DayAndString ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Encoding.StrictTextBuilder Day where
-  to = from . to @String
-  maybeFrom = maybeFrom @String . to
-
-#elif MIN_VERSION_text(2,0,2)
-
-import qualified Data.Text.Encoding
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.StrictTextBuilderAndString ()
-import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.DayAndString ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Encoding.StrictBuilder Day where
-  to = from . to @String
-  maybeFrom = maybeFrom @String . to
-
-#endif
diff --git a/src/library/LawfulConversions/Relations/DayAndString.hs b/src/library/LawfulConversions/Relations/DayAndString.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/DayAndString.hs
+++ /dev/null
@@ -1,13 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.DayAndString where
-
-import Data.Time
-import Data.Time.Format.ISO8601
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | Implements ISO-8601.
-instance IsSome String Day where
-  to = iso8601Show
-  maybeFrom = iso8601ParseM
diff --git a/src/library/LawfulConversions/Relations/DayAndText.hs b/src/library/LawfulConversions/Relations/DayAndText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/DayAndText.hs
+++ /dev/null
@@ -1,14 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.DayAndText where
-
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.DayAndString ()
-import LawfulConversions.Relations.StringAndText ()
-
--- | Implements ISO-8601.
-instance IsSome Text Day where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/Int16AndWord16.hs b/src/library/LawfulConversions/Relations/Int16AndWord16.hs
--- a/src/library/LawfulConversions/Relations/Int16AndWord16.hs
+++ b/src/library/LawfulConversions/Relations/Int16AndWord16.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.Int16AndWord16 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Int16 Word16 where
diff --git a/src/library/LawfulConversions/Relations/Int32AndWord32.hs b/src/library/LawfulConversions/Relations/Int32AndWord32.hs
--- a/src/library/LawfulConversions/Relations/Int32AndWord32.hs
+++ b/src/library/LawfulConversions/Relations/Int32AndWord32.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.Int32AndWord32 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Int32 Word32 where
diff --git a/src/library/LawfulConversions/Relations/Int64AndWord64.hs b/src/library/LawfulConversions/Relations/Int64AndWord64.hs
--- a/src/library/LawfulConversions/Relations/Int64AndWord64.hs
+++ b/src/library/LawfulConversions/Relations/Int64AndWord64.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.Int64AndWord64 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Int64 Word64 where
diff --git a/src/library/LawfulConversions/Relations/Int8AndWord8.hs b/src/library/LawfulConversions/Relations/Int8AndWord8.hs
--- a/src/library/LawfulConversions/Relations/Int8AndWord8.hs
+++ b/src/library/LawfulConversions/Relations/Int8AndWord8.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.Int8AndWord8 where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Int8 Word8 where
diff --git a/src/library/LawfulConversions/Relations/IntAndWord.hs b/src/library/LawfulConversions/Relations/IntAndWord.hs
--- a/src/library/LawfulConversions/Relations/IntAndWord.hs
+++ b/src/library/LawfulConversions/Relations/IntAndWord.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.IntAndWord where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Int Word where
diff --git a/src/library/LawfulConversions/Relations/IntMapAndMapOfInt.hs b/src/library/LawfulConversions/Relations/IntMapAndMapOfInt.hs
--- a/src/library/LawfulConversions/Relations/IntMapAndMapOfInt.hs
+++ b/src/library/LawfulConversions/Relations/IntMapAndMapOfInt.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.IntMap.Strict
 import qualified Data.Map.Strict
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome (Map Int v) (IntMap v) where
diff --git a/src/library/LawfulConversions/Relations/IntSetAndSetOfInt.hs b/src/library/LawfulConversions/Relations/IntSetAndSetOfInt.hs
--- a/src/library/LawfulConversions/Relations/IntSetAndSetOfInt.hs
+++ b/src/library/LawfulConversions/Relations/IntSetAndSetOfInt.hs
@@ -2,7 +2,7 @@
 
 module LawfulConversions.Relations.IntSetAndSetOfInt where
 
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome (Set Int) IntSet where
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndLazyByteStringBuilder.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndLazyByteStringBuilder.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndLazyByteStringBuilder.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringAndLazyByteStringBuilder.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.ByteString.Builder
 import qualified Data.ByteString.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 
 instance IsSome Data.ByteString.Lazy.ByteString Data.ByteString.Builder.Builder where
   to = Data.ByteString.Builder.toLazyByteString
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndLazyText.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndLazyText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndLazyText.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyByteStringAndLazyText where
-
-import qualified Data.ByteString.Lazy
-import qualified Data.Text.Encoding.Error
-import qualified Data.Text.Lazy
-import qualified Data.Text.Lazy.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome Data.ByteString.Lazy.ByteString Data.Text.Lazy.Text where
-  to = Data.Text.Lazy.Encoding.encodeUtf8
-  maybeFrom = either (const Nothing) Just . Data.Text.Lazy.Encoding.decodeUtf8'
-
--- | Lenient UTF-8 decoding.
-instance IsMany Data.ByteString.Lazy.ByteString Data.Text.Lazy.Text where
-  from = Data.Text.Lazy.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndShortByteString.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndShortByteString.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndShortByteString.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringAndShortByteString.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.ByteString.Lazy
 import qualified Data.ByteString.Short
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.ByteString.Lazy.ByteString Data.ByteString.Short.ShortByteString where
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndString.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndString.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndString.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyByteStringAndString where
-
-import qualified Data.ByteString.Lazy
-import qualified Data.Text.Encoding.Error
-import qualified Data.Text.Lazy
-import qualified Data.Text.Lazy.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome Data.ByteString.Lazy.ByteString String where
-  to = Data.Text.Lazy.Encoding.encodeUtf8 . Data.Text.Lazy.pack
-  maybeFrom = either (const Nothing) (Just . Data.Text.Lazy.unpack) . Data.Text.Lazy.Encoding.decodeUtf8'
-
--- | Lenient UTF-8 decoding.
-instance IsMany Data.ByteString.Lazy.ByteString String where
-  from = Data.Text.Lazy.unpack . Data.Text.Lazy.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndText.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndText.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndText.hs
+++ /dev/null
@@ -1,20 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyByteStringAndText where
-
-import qualified Data.ByteString.Lazy
-import qualified Data.Text
-import qualified Data.Text.Encoding.Error
-import qualified Data.Text.Lazy
-import qualified Data.Text.Lazy.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | UTF-8 codec.
-instance IsSome Data.ByteString.Lazy.ByteString Data.Text.Text where
-  to = Data.Text.Lazy.Encoding.encodeUtf8 . Data.Text.Lazy.fromStrict
-  maybeFrom = either (const Nothing) (Just . Data.Text.Lazy.toStrict) . Data.Text.Lazy.Encoding.decodeUtf8'
-
--- | Lenient UTF-8 decoding.
-instance IsMany Data.ByteString.Lazy.ByteString Data.Text.Text where
-  from = Data.Text.Lazy.toStrict . Data.Text.Lazy.Encoding.decodeUtf8With Data.Text.Encoding.Error.lenientDecode
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndTextArray.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndTextArray.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndTextArray.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringAndTextArray.hs
@@ -8,7 +8,7 @@
 import qualified Data.ByteString.Lazy
 import qualified Data.ByteString.Short
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringAndWord8List.hs b/src/library/LawfulConversions/Relations/LazyByteStringAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringAndWord8List.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.LazyByteStringAndWord8List where
 
 import qualified Data.ByteString.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.ByteString.Lazy.ByteString [Word8] where
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndShortByteString.hs b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndShortByteString.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndShortByteString.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndShortByteString.hs
@@ -5,7 +5,7 @@
 import qualified Data.ByteString.Builder
 import qualified Data.ByteString.Lazy
 import qualified Data.ByteString.Short
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.ByteString.Builder.Builder Data.ByteString.Short.ShortByteString where
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndTextArray.hs b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndTextArray.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndTextArray.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndTextArray.hs
@@ -9,7 +9,7 @@
 import qualified Data.ByteString.Lazy
 import qualified Data.ByteString.Short
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndWord8List.hs b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/LazyByteStringBuilderAndWord8List.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.ByteString.Builder
 import qualified Data.ByteString.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.ByteString.Builder.Builder [Word8] where
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndLazyTextBuilder.hs b/src/library/LawfulConversions/Relations/LazyTextAndLazyTextBuilder.hs
--- a/src/library/LawfulConversions/Relations/LazyTextAndLazyTextBuilder.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextAndLazyTextBuilder.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Builder
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Text Data.Text.Lazy.Builder.Builder where
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndStrictTextBuilder.hs b/src/library/LawfulConversions/Relations/LazyTextAndStrictTextBuilder.hs
--- a/src/library/LawfulConversions/Relations/LazyTextAndStrictTextBuilder.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextAndStrictTextBuilder.hs
@@ -7,7 +7,7 @@
 
 import qualified Data.Text.Encoding
 import qualified Data.Text.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Text Data.Text.Encoding.StrictTextBuilder where
@@ -28,7 +28,7 @@
 
 import qualified Data.Text.Encoding
 import qualified Data.Text.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Text Data.Text.Encoding.StrictBuilder where
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndString.hs b/src/library/LawfulConversions/Relations/LazyTextAndString.hs
--- a/src/library/LawfulConversions/Relations/LazyTextAndString.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextAndString.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.LazyTextAndString where
 
 import qualified Data.Text.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.StringAndText ()
 
@@ -12,4 +12,4 @@
   maybeFrom = fmap Data.Text.Lazy.fromStrict . maybeFrom
 
 instance IsMany String Data.Text.Lazy.Text where
-  from = fromString
+  onfrom = fromString
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndText.hs b/src/library/LawfulConversions/Relations/LazyTextAndText.hs
--- a/src/library/LawfulConversions/Relations/LazyTextAndText.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextAndText.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.LazyTextAndText where
 
 import qualified Data.Text.Lazy
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Text Text where
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndUtcTime.hs b/src/library/LawfulConversions/Relations/LazyTextAndUtcTime.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyTextAndUtcTime.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyTextAndUtcTime where
-
-import qualified Data.Text.Lazy
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.LazyTextAndString ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Lazy.Text UTCTime where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/LazyTextAndUuid.hs b/src/library/LawfulConversions/Relations/LazyTextAndUuid.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyTextAndUuid.hs
+++ /dev/null
@@ -1,12 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyTextAndUuid where
-
-import qualified Data.Text.Lazy
-import qualified Data.UUID.Types
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome Data.Text.Lazy.Text UUID where
-  to = Data.Text.Lazy.fromStrict . Data.UUID.Types.toText
-  maybeFrom = Data.UUID.Types.fromText . Data.Text.Lazy.toStrict
diff --git a/src/library/LawfulConversions/Relations/LazyTextBuilderAndStrictTextBuilder.hs b/src/library/LawfulConversions/Relations/LazyTextBuilderAndStrictTextBuilder.hs
--- a/src/library/LawfulConversions/Relations/LazyTextBuilderAndStrictTextBuilder.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextBuilderAndStrictTextBuilder.hs
@@ -8,7 +8,7 @@
 import qualified Data.Text.Encoding
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Builder
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Builder.Builder Data.Text.Encoding.StrictTextBuilder where
@@ -30,7 +30,7 @@
 import qualified Data.Text.Encoding
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Builder
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Builder.Builder Data.Text.Encoding.StrictBuilder where
diff --git a/src/library/LawfulConversions/Relations/LazyTextBuilderAndString.hs b/src/library/LawfulConversions/Relations/LazyTextBuilderAndString.hs
--- a/src/library/LawfulConversions/Relations/LazyTextBuilderAndString.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextBuilderAndString.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Builder
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.StringAndText ()
 
@@ -13,4 +13,4 @@
   maybeFrom = fmap Data.Text.Lazy.Builder.fromText . maybeFrom
 
 instance IsMany String Data.Text.Lazy.Builder.Builder where
-  from = fromString
+  onfrom = fromString
diff --git a/src/library/LawfulConversions/Relations/LazyTextBuilderAndText.hs b/src/library/LawfulConversions/Relations/LazyTextBuilderAndText.hs
--- a/src/library/LawfulConversions/Relations/LazyTextBuilderAndText.hs
+++ b/src/library/LawfulConversions/Relations/LazyTextBuilderAndText.hs
@@ -4,7 +4,7 @@
 
 import qualified Data.Text.Lazy
 import qualified Data.Text.Lazy.Builder
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Data.Text.Lazy.Builder.Builder Text where
diff --git a/src/library/LawfulConversions/Relations/LazyTextBuilderAndUtcTime.hs b/src/library/LawfulConversions/Relations/LazyTextBuilderAndUtcTime.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyTextBuilderAndUtcTime.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyTextBuilderAndUtcTime where
-
-import qualified Data.Text.Lazy.Builder
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.LazyTextBuilderAndString ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Lazy.Builder.Builder UTCTime where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/LazyTextBuilderAndUuid.hs b/src/library/LawfulConversions/Relations/LazyTextBuilderAndUuid.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/LazyTextBuilderAndUuid.hs
+++ /dev/null
@@ -1,13 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.LazyTextBuilderAndUuid where
-
-import qualified Data.Text.Lazy
-import qualified Data.Text.Lazy.Builder
-import qualified Data.UUID.Types
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome Data.Text.Lazy.Builder.Builder UUID where
-  to = Data.Text.Lazy.Builder.fromText . Data.UUID.Types.toText
-  maybeFrom = Data.UUID.Types.fromText . Data.Text.Lazy.toStrict . Data.Text.Lazy.Builder.toLazyText
diff --git a/src/library/LawfulConversions/Relations/ListAndSeq.hs b/src/library/LawfulConversions/Relations/ListAndSeq.hs
--- a/src/library/LawfulConversions/Relations/ListAndSeq.hs
+++ b/src/library/LawfulConversions/Relations/ListAndSeq.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ListAndSeq where
 
 import qualified Data.Sequence
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome [a] (Seq a) where
diff --git a/src/library/LawfulConversions/Relations/ShortByteStringAndTextArray.hs b/src/library/LawfulConversions/Relations/ShortByteStringAndTextArray.hs
--- a/src/library/LawfulConversions/Relations/ShortByteStringAndTextArray.hs
+++ b/src/library/LawfulConversions/Relations/ShortByteStringAndTextArray.hs
@@ -7,7 +7,7 @@
 
 import qualified Data.ByteString.Short
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/ShortByteStringAndWord8List.hs b/src/library/LawfulConversions/Relations/ShortByteStringAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/ShortByteStringAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/ShortByteStringAndWord8List.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.ShortByteStringAndWord8List where
 
 import qualified Data.ByteString.Short
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import LawfulConversions.Relations.ByteArrayAndShortByteString ()
 
diff --git a/src/library/LawfulConversions/Relations/StrictTextBuilderAndString.hs b/src/library/LawfulConversions/Relations/StrictTextBuilderAndString.hs
--- a/src/library/LawfulConversions/Relations/StrictTextBuilderAndString.hs
+++ b/src/library/LawfulConversions/Relations/StrictTextBuilderAndString.hs
@@ -6,7 +6,7 @@
 #if MIN_VERSION_text(2,1,2)
 
 import qualified Data.Text.Encoding
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Relations.StringAndText ()
 import LawfulConversions.Prelude
 
@@ -15,12 +15,12 @@
   maybeFrom = fmap Data.Text.Encoding.textToStrictBuilder . maybeFrom
 
 instance IsMany String Data.Text.Encoding.StrictTextBuilder where
-  from =  Data.Text.Encoding.textToStrictBuilder . from
+  onfrom =  Data.Text.Encoding.textToStrictBuilder . onfrom
 
 #elif MIN_VERSION_text(2,0,2)
 
 import qualified Data.Text.Encoding
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Relations.StringAndText ()
 import LawfulConversions.Prelude
 
@@ -29,6 +29,6 @@
   maybeFrom = fmap Data.Text.Encoding.textToStrictBuilder . maybeFrom
 
 instance IsMany String Data.Text.Encoding.StrictBuilder where
-  from =  Data.Text.Encoding.textToStrictBuilder . from
+  onfrom =  Data.Text.Encoding.textToStrictBuilder . onfrom
 
 #endif
diff --git a/src/library/LawfulConversions/Relations/StrictTextBuilderAndText.hs b/src/library/LawfulConversions/Relations/StrictTextBuilderAndText.hs
--- a/src/library/LawfulConversions/Relations/StrictTextBuilderAndText.hs
+++ b/src/library/LawfulConversions/Relations/StrictTextBuilderAndText.hs
@@ -6,7 +6,7 @@
 #if MIN_VERSION_text(2,1,2)
 
 import qualified Data.Text.Encoding
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Text Data.Text.Encoding.StrictTextBuilder where
@@ -26,7 +26,7 @@
 #elif MIN_VERSION_text(2,0,2)
 
 import qualified Data.Text.Encoding
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome Text Data.Text.Encoding.StrictBuilder where
diff --git a/src/library/LawfulConversions/Relations/StrictTextBuilderAndUtcTime.hs b/src/library/LawfulConversions/Relations/StrictTextBuilderAndUtcTime.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/StrictTextBuilderAndUtcTime.hs
+++ /dev/null
@@ -1,36 +0,0 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.StrictTextBuilderAndUtcTime where
-
-#if MIN_VERSION_text(2,1,2)
-
-import qualified Data.Text.Encoding
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.StrictTextBuilderAndString ()
-import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Encoding.StrictTextBuilder UTCTime where
-  to = from . to @String
-  maybeFrom = maybeFrom @String . to
-
-#elif MIN_VERSION_text(2,0,2)
-
-import qualified Data.Text.Encoding
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.StrictTextBuilderAndString ()
-import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-
--- | Implements ISO-8601.
-instance IsSome Data.Text.Encoding.StrictBuilder UTCTime where
-  to = from . to @String
-  maybeFrom = maybeFrom @String . to
-
-#endif
diff --git a/src/library/LawfulConversions/Relations/StrictTextBuilderAndUuid.hs b/src/library/LawfulConversions/Relations/StrictTextBuilderAndUuid.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/StrictTextBuilderAndUuid.hs
+++ /dev/null
@@ -1,28 +0,0 @@
-{-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.StrictTextBuilderAndUuid where
-
-#if MIN_VERSION_text(2,1,2)
-
-import qualified Data.UUID.Types
-import qualified Data.Text.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome Data.Text.Encoding.StrictTextBuilder UUID where
-  to = Data.Text.Encoding.textToStrictBuilder . Data.UUID.Types.toText
-  maybeFrom = Data.UUID.Types.fromText . Data.Text.Encoding.strictBuilderToText
-
-#elif MIN_VERSION_text(2,0,2)
-
-import qualified Data.UUID.Types
-import qualified Data.Text.Encoding
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome Data.Text.Encoding.StrictBuilder UUID where
-  to = Data.Text.Encoding.textToStrictBuilder . Data.UUID.Types.toText
-  maybeFrom = Data.UUID.Types.fromText . Data.Text.Encoding.strictBuilderToText
-
-#endif
diff --git a/src/library/LawfulConversions/Relations/StringAndText.hs b/src/library/LawfulConversions/Relations/StringAndText.hs
--- a/src/library/LawfulConversions/Relations/StringAndText.hs
+++ b/src/library/LawfulConversions/Relations/StringAndText.hs
@@ -3,7 +3,7 @@
 module LawfulConversions.Relations.StringAndText where
 
 import qualified Data.Text as Text
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 
 instance IsSome String Text where
@@ -16,4 +16,4 @@
           else Nothing
 
 instance IsMany String Text where
-  from = Text.pack
+  onfrom = Text.pack
diff --git a/src/library/LawfulConversions/Relations/StringAndUtcTime.hs b/src/library/LawfulConversions/Relations/StringAndUtcTime.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/StringAndUtcTime.hs
+++ /dev/null
@@ -1,13 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.StringAndUtcTime where
-
-import Data.Time
-import Data.Time.Format.ISO8601
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
--- | Implements ISO-8601.
-instance IsSome String UTCTime where
-  to = iso8601Show
-  maybeFrom = iso8601ParseM
diff --git a/src/library/LawfulConversions/Relations/StringAndUuid.hs b/src/library/LawfulConversions/Relations/StringAndUuid.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/StringAndUuid.hs
+++ /dev/null
@@ -1,11 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.StringAndUuid where
-
-import qualified Data.UUID.Types
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome String UUID where
-  to = Data.UUID.Types.toString
-  maybeFrom = Data.UUID.Types.fromString
diff --git a/src/library/LawfulConversions/Relations/TextAndUtcTime.hs b/src/library/LawfulConversions/Relations/TextAndUtcTime.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/TextAndUtcTime.hs
+++ /dev/null
@@ -1,14 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.TextAndUtcTime where
-
-import Data.Time
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-import LawfulConversions.Relations.StringAndText ()
-import LawfulConversions.Relations.StringAndUtcTime ()
-
--- | Implements ISO-8601.
-instance IsSome Text UTCTime where
-  to = fromString . to
-  maybeFrom = maybeFrom @String . to
diff --git a/src/library/LawfulConversions/Relations/TextAndUuid.hs b/src/library/LawfulConversions/Relations/TextAndUuid.hs
deleted file mode 100644
--- a/src/library/LawfulConversions/Relations/TextAndUuid.hs
+++ /dev/null
@@ -1,11 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-
-module LawfulConversions.Relations.TextAndUuid where
-
-import qualified Data.UUID.Types as Uuid
-import LawfulConversions.Classes
-import LawfulConversions.Prelude
-
-instance IsSome Text UUID where
-  to = Uuid.toText
-  maybeFrom = Uuid.fromText
diff --git a/src/library/LawfulConversions/Relations/TextArrayAndWord8List.hs b/src/library/LawfulConversions/Relations/TextArrayAndWord8List.hs
--- a/src/library/LawfulConversions/Relations/TextArrayAndWord8List.hs
+++ b/src/library/LawfulConversions/Relations/TextArrayAndWord8List.hs
@@ -7,7 +7,7 @@
 
 import qualified Data.ByteString.Short
 import qualified Data.Text.Array
-import LawfulConversions.Classes
+import LawfulConversions.Algebra
 import LawfulConversions.Prelude
 import qualified LawfulConversions.TextCompat.Array
 
diff --git a/src/library/LawfulConversions/Relations/Void.hs b/src/library/LawfulConversions/Relations/Void.hs
new file mode 100644
--- /dev/null
+++ b/src/library/LawfulConversions/Relations/Void.hs
@@ -0,0 +1,11 @@
+{-# OPTIONS_GHC -Wno-orphans #-}
+
+module LawfulConversions.Relations.Void where
+
+import LawfulConversions.Algebra
+import LawfulConversions.Prelude
+
+-- | The empty set has no elements, and therefore is vacuously a subset of any set.
+instance IsSome a Void where
+  to = absurd
+  maybeFrom = const Nothing
diff --git a/src/test/Main.hs b/src/test/Main.hs
--- a/src/test/Main.hs
+++ b/src/test/Main.hs
@@ -110,33 +110,12 @@
       testIs @Word64 @Int64 Proxy Proxy,
       testIs @Word64 @Word64 Proxy Proxy,
       testIs @Word8 @Int8 Proxy Proxy,
-      testIs @Word8 @Word8 Proxy Proxy,
-      testIsSome @Data.Text.Lazy.Text @UTCTime Proxy Proxy,
-      testIsSome @Data.Text.Lazy.Builder.Builder @UTCTime Proxy Proxy,
-      testIsSome @String @UTCTime Proxy Proxy,
-      testIsSome @Text @UTCTime Proxy Proxy,
-      testIsSome @Data.Text.Lazy.Text @Day Proxy Proxy,
-      testIsSome @Data.Text.Lazy.Builder.Builder @Day Proxy Proxy,
-      testIsSome @String @Day Proxy Proxy,
-      testIsSome @Text @Day Proxy Proxy
+      testIs @Word8 @Word8 Proxy Proxy
     ]
 
 testIs :: (Is a b, Eq a, Eq b, Arbitrary a, Show a, Arbitrary b, Show b, Typeable a, Typeable b) => Proxy a -> Proxy b -> TestTree
 testIs superp subp =
   isProperties superp subp
-    & fmap (uncurry testProperty)
-    & testGroup groupName
-  where
-    groupName =
-      mconcat
-        [ show (typeOf (asProxyTypeOf undefined superp)),
-          "/",
-          show (typeOf (asProxyTypeOf undefined subp))
-        ]
-
-testIsSome :: (IsSome a b, Eq a, Eq b, Arbitrary a, Show a, Arbitrary b, Show b, Typeable a, Typeable b) => Proxy a -> Proxy b -> TestTree
-testIsSome superp subp =
-  isSomeProperties superp subp
     & fmap (uncurry testProperty)
     & testGroup groupName
   where