+paty (TransCoercion t1 t2) =
+ parens (sep ([pqname transCoercion, pbty t1, pbty t2]))
+paty (SymCoercion t) =
+ parens (sep [pqname symCoercion, paty t])
+paty (UnsafeCoercion t1 t2) =
+ parens (sep [pqname unsafeCoercion, pbty t1, pbty t2])
+paty (LeftCoercion t) =
+ parens (pqname leftCoercion <+> paty t)
+paty (RightCoercion t) =
+ parens (pqname rightCoercion <+> paty t)