fact: Definition left_sum_lift (X Y:Type) (A:X->X->Prop) (x y : X+Y) := match (x,y) with | (inl x0, inl y0) => A x0 y0 | (inl x0, inr y0) => False | (inr x0, inl y0) => False | (inr x0, inr y0) => True end.
imports: Coq(Arith Wf_nat Lia) AlmostFull.PropBounded(AlmostFull)