diff --git a/language-ats.cabal b/language-ats.cabal
--- a/language-ats.cabal
+++ b/language-ats.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.18
 name: language-ats
-version: 1.2.0.4
+version: 1.2.0.5
 license: BSD3
 license-file: LICENSE
 copyright: Copyright: (c) 2018 Vanessa McHale
diff --git a/src/Language/ATS/Lexer.x b/src/Language/ATS/Lexer.x
--- a/src/Language/ATS/Lexer.x
+++ b/src/Language/ATS/Lexer.x
@@ -244,7 +244,7 @@
     <0> exception                { tok (\p _ -> alex $ Keyword p KwException) }
     <0> "$list_vt"               { tok (\p _ -> alex $ Keyword p (KwListLit "_vt")) }
     <0> "$list"                  { tok (\p _ -> alex $ Keyword p (KwListLit mempty)) }
-    <0> "fold@"                  { tok (\p s -> alex $ IdentifierSpace p s) }
+    <0> "fold@"                  { tok (\p s -> alex $ Identifier p s) }
     <0> "free@"                  { tok (\p s -> alex $ Identifier p s) }
     <0> @fixity_decl             { tok (\p s -> alex $ FixityTok p s) }
 
diff --git a/src/Language/ATS/Parser.y b/src/Language/ATS/Parser.y
--- a/src/Language/ATS/Parser.y
+++ b/src/Language/ATS/Parser.y
@@ -146,6 +146,7 @@
     identifierSpace { $$@IdentifierSpace{} }
     closeParen { Special $$ ")" }
     openParen { Special $$ "(" }
+    boxTuple { Special $$ "'(" }
     colon { SignatureTok $$ "" }
     signature { SignatureTok _ $$ }
     comma { Special $$ "," }
@@ -282,6 +283,8 @@
      | identifierSpace identifier { Dependent (Unqualified $ to_string $1) [Named (Unqualified $ to_string $2)] }
      | openParen TypeIn closeParen { Tuple $1 $2 }
      | openParen TypeIn closeParen lineComment { Tuple $1 $2 }
+     | boxTuple TypeIn closeParen { BoxTuple $1 $2 }
+     | boxTuple TypeIn closeParen lineComment { BoxTuple $1 $2 }
      | openParen Type closeParen { ParenType $1 $2 }
      | openParen TypeIn rbrace {% left $ Expected $3 ")" "}" }
      | doubleParens { NoneType $1 }
@@ -439,6 +442,7 @@
               | Literal { $1 }
               | Call { $1 }
               | openParen Tuple closeParen { TupleEx $1 $2 }
+              | boxTuple Tuple closeParen { BoxTupleEx $1 $2 }
               | case Expression of Case { Case $3 $1 $2 $4 }
               | ifcase IfCase { IfCase $1 $2 }
               | openParen Expression closeParen { ParenExpr $1 $2 }
@@ -452,6 +456,7 @@
               | let ATS comment_after(in) end { Let $1 $2 Nothing }
               | let ATS in Expression end { Let $1 $2 (Just $4) }
               | let ATS in Expression vbar {% left $ Expected $5 "end" "|" }
+              | let ATS fun {% left $ Expected $3 "in" "fun" }
               | lambda Pattern LambdaArrow Expression { Lambda $1 $3 $2 $4 }
               | llambda Pattern LambdaArrow Expression { LinearLambda $1 $3 $2 $4 }
               | addrAt PreExpression { AddrAt $1 $2 }
@@ -888,7 +893,8 @@
             | overload BinOp with identifierSpace of intLit { OverloadOp $1 $2 (Unqualified $ to_string $4) (Just $6) }
             | overload identifierSpace with Name { OverloadIdent $1 (to_string $2) $4 Nothing }
             | overload identifierSpace with identifierSpace of intLit { OverloadIdent $1 (to_string $2) (Unqualified $ to_string $4) (Just $6) }
-            | overload tilde with identifierSpace of intLit { OverloadIdent $1 "~" (Unqualified $ to_string $4) (Just $6) } -- FIXME figure out a general solution.
+            | overload tilde with identifier { OverloadIdent $1 "~" (Unqualified $ to_string $4) Nothing } -- FIXME figure out a general solution.
+            | overload tilde with identifierSpace of intLit { OverloadIdent $1 "~" (Unqualified $ to_string $4) (Just $6) }
             | overload lsqbracket rsqbracket with identifierSpace of intLit { OverloadIdent $1 "[]" (Unqualified $ to_string $5) (Just $7) }
             | overload dot identifierSpace with Name { OverloadIdent $1 ('.' : (to_string $3)) $5 Nothing }
             | assume identifierSpace eq Type { Assume (Unqualified (to_string $2)) [NoArgs] $4 }
diff --git a/src/Language/ATS/PrettyPrint.hs b/src/Language/ATS/PrettyPrint.hs
--- a/src/Language/ATS/PrettyPrint.hs
+++ b/src/Language/ATS/PrettyPrint.hs
@@ -165,6 +165,7 @@
         a (TypeSignatureF e t)         = e <+> ":" <+> pretty t
         a (WhereExpF e d)              = e <+> "where" <$> braces (" " <> nest 2 (pretty d) <> " ")
         a (TupleExF _ es)              = parens (mconcat $ punctuate ", " (reverse es))
+        a (BoxTupleExF _ es)           = "'(" <> mconcat (punctuate ", " (reverse es)) <> ")"
         a (WhileF _ e e')              = "while" <> parens e <> e'
         a (ActionsF as)                = "{" <$> indent 2 (pretty as) <$> "}"
         a UnderscoreLitF{}             = "_"
@@ -266,7 +267,7 @@
         a (NamedF n)                       = pretty n
         a (ViewTypeF _ t)                  = "view@" <> parens t
         a (ExF e (Just t))
-            | head (show t) == '['         = pretty e <> t -- FIXME this is a hack
+            | head (show t) == '['         = pretty e <> t -- FIXME this is kinda dumb
             | otherwise                    = pretty e <+> t
         a (ExF e Nothing)                  = pretty e
         a (DependentF n@SpecialName{} [t]) = pretty n <+> pretty t
@@ -282,6 +283,7 @@
         a (ProofTypeF _ t t')              = parens (prettyArgsG "" "" t <+> "|" <+> t')
         a (ConcreteTypeF e)                = pretty e
         a (TupleF _ ts)                    = parens (mconcat (punctuate ", " (fmap pretty (reverse ts))))
+        a (BoxTupleF _ ts)                 = "'(" <> mconcat (punctuate ", " (fmap pretty (reverse ts))) <> ")"
         a (RefTypeF t)                     = "&" <> t
         a (FunctionTypeF s t t')           = t <+> string s <+> t'
         a (ViewLiteralF c)                 = "view" <> pretty c
diff --git a/src/Language/ATS/Types.hs b/src/Language/ATS/Types.hs
--- a/src/Language/ATS/Types.hs
+++ b/src/Language/ATS/Types.hs
@@ -148,6 +148,7 @@
 
 -- | A type for parsed ATS types
 data Type a = Tuple a [Type a]
+            | BoxTuple a [Type a]
             | Named (Name a)
             | Ex (Existential a) (Maybe (Type a))
             | ForA (Universal a) (Type a)
@@ -314,7 +315,8 @@
                   | ProofExpr a (Expression a) (Expression a)
                   | TypeSignature (Expression a) (Type a)
                   | WhereExp (Expression a) (ATS a)
-                  | TupleEx a [Expression a] -- TODO support boxed tuples
+                  | TupleEx a [Expression a]
+                  | BoxTupleEx a [Expression a]
                   | While a (Expression a) (Expression a)
                   | Actions (ATS a)
                   | Begin a (Expression a)