diff --git a/predicate-transformers.cabal b/predicate-transformers.cabal
--- a/predicate-transformers.cabal
+++ b/predicate-transformers.cabal
@@ -1,7 +1,7 @@
 cabal-version:       2.4
 
 name:                predicate-transformers
-version:             0.5.0.0
+version:             0.6.0.0
 synopsis:            A library for writing predicates and transformations over predicates in Haskell
 description:
   This package provides ways to write predicates such that they compose nicely and are easy to debug.
diff --git a/src/PredicateTransformers.hs b/src/PredicateTransformers.hs
--- a/src/PredicateTransformers.hs
+++ b/src/PredicateTransformers.hs
@@ -72,7 +72,7 @@
 only _ _ = False
 {-# inlinable only #-}
 
--- |Only test the `k`th element of a foldable.
+-- |Only test the @k@th element of a foldable.
 kth :: Foldable f => Int -> PT a (f a)
 kth k p = startingWith p . drop k . toList
 {-# inlinable kth #-}
@@ -97,7 +97,7 @@
 {-# inlinable dist #-}
 
 -- |Given a representable functor-full of predicates, and a functor-full of values,
--- yield a representable functor-full of booleans. Similar to `distF`.
+-- yield a representable functor-full of booleans. Similar to `dist`.
 distRep :: Representable f =>
     f (a -> Bool) -> f a -> f Bool
 distRep pr fa = tabulate (\r -> index pr r $ index fa r)
@@ -123,7 +123,7 @@
 pair f s (a,b) = f a && s b
 {-# inline conlike pair #-}
 
--- |Flipped function composition; `f !` for a function `f` is a predicate transformer.
+-- |Flipped function composition; @f !@ for a function @f@ is a predicate transformer.
 (!) :: (b -> a) -> (a -> c) -> b -> c
 (!) = flip (.)
 {-# inline conlike (!) #-}
@@ -131,3 +131,15 @@
 -- |Prints the input of a predicate, for debugging.
 traced :: Show a => (a -> c) -> a -> c
 traced p a = traceShow a (p a)
+{-# inline traced #-}
+
+-- |Prints the input of a predicate, if the predicate fails.
+traceFailure :: Show a => PT a a
+traceFailure p a = if p a then True else traceShow a False
+{-# inline traceFailure #-}
+
+-- |Predicate which always succeeds.
+something :: Pred a
+something = const True
+{-# inline something #-}
+