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