mkWpFun (WpCast co1) (WpCast co2) _  _  = WpCast (mkTcFunCo Representational (mkTcSymCo co1) co2)
mkWpFun (WpCast co1) (WpCast co2) _  _  = WpCast (mkTcFunCo Representational (mkTcSymCo co1) co2)
mkWpFun (WpCast co1) (WpCast co2) _  _  = WpCast (mkTcFunCo Representational (mkTcSymCo co1) co2)