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diff --git a/testsuite/tests/polykinds/T19094.hs b/testsuite/tests/polykinds/T19094.hs
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+++ b/testsuite/tests/polykinds/T19094.hs
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+{-# Language RankNTypes, TypeApplications, PolyKinds, DataKinds, TypeOperators, StandaloneKindSignatures, TypeFamilies, FlexibleInstances, MultiParamTypeClasses #-}
+
+module T19094 where
+
+import Data.Type.Equality
+import Data.Kind
+
+type PolyKinded :: Type -> Type
+type PolyKinded res = (forall (k :: Type). k -> res)
+
+infix 4
+ ===
+type
+ (===) :: PolyKinded (PolyKinded Bool)
+type family
+ a === b where
+ a === a = True
+ _ === _ = False
+
+type  TryUnify :: Bool -> PolyKinded (PolyKinded Constraint)
+class (a === b) ~ cond
+   => TryUnify cond a b
+instance (a === b) ~ False
+      => TryUnify False @k a @j b
+instance {-# Incoherent #-}
+         ( (a === b) ~ True
+         , a ~~ b
+         )
+      => TryUnify True @k a @j b