-- | Extract the 'TyVar's bound by a vanilla type synonym
-- and the corresponding (unsubstituted) right hand side.
synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type)
synTyConDefn_maybe (SynonymTyCon {tyConTyVars = tyvars, synTcRhs = ty})
  = Just (tyvars, ty)
synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type)
synTyConDefn_maybe (SynonymTyCon {tyConTyVars = tyvars, synTcRhs = ty})
  = Just (tyvars, ty)
synTyConDefn_maybe (SynonymTyCon {tyConTyVars = tyvars, synTcRhs = ty})
  = Just (tyvars, ty)