; L loc pred' <- cvtPred ty
; inst_ty' <- returnL $ mkImplicitHsForAllTy ctxt' (L loc (HsPredTy pred'))
; returnL $ InstD (InstDecl inst_ty' binds' sigs' [])
; L loc pred' <- cvtPred ty
; inst_ty' <- returnL $ mkImplicitHsForAllTy ctxt' (L loc (HsPredTy pred'))
; returnL $ InstD (InstDecl inst_ty' binds' sigs' [])