                                         env1 <- extvars (tybound (q++q')) env
                                         TSchema l <$> kchkQBinds env1 (q++q') <*> kexp KType env1 t
      where ambig                   = qualbound q \\ closeDepVarsQ (tyfree t) q

kchkQBinds env []                   = return []
kchkQBinds env (Quant v us : q)     = do us <- kchkBounds env us
                                         q <- kchkQBinds env q
                                         return $ Quant v us : q

kchkBounds env []                   = return []