remove square brackets around type lines

(parens are needed if they are anything other than a `term arg`)

lib/Quox/Parser/Parser.idr

@@ -245,15 +245,6 @@ export
 term : FileName -> Grammar True PTerm
 -- defined after all the subterm parsers
 
-export
-typeLine : FileName -> Grammar True (PatVar, PTerm)
-typeLine fname = do
-  resC "["
-  mustWork $ do
-    i <- patVar fname <* resC "⇒" <|> unused fname
-    t <- assert_total term fname <* needRes "]"
-    pure (i, t)
-
 ||| box term `[t]` or type `[π.A]`
 export
 boxTerm : FileName -> Grammar True PTerm
@@ -287,6 +278,19 @@ termArg fname = withLoc fname $
   <|> [|V qname|]
   <|> const <$> tupleTerm fname
 
+export
+properTypeLine : FileName -> Grammar True (PatVar, PTerm)
+properTypeLine fname = do
+  resC "("
+  i <- patVar fname <* resC "⇒" <|> unused fname
+  t <- assert_total term fname <* needRes ")"
+  pure (i, t)
+
+export
+typeLine : FileName -> Grammar True (PatVar, PTerm)
+typeLine fname =
+  properTypeLine fname <|> [|(,) (unused fname) (termArg fname)|]
+
 ||| optionally, two dimension arguments. if absent default to `@0 @1`
 private
 optDirection : FileName -> Grammar False (PDim, PDim)