proposition: Theorem DisjointIncl : forall L1 L2 L3 L4 : list A, Disjoint L1 L2 -> InclEq L3 L1 -> InclEq L4 L2 -> Disjoint L3 L4.
proof: Proof. intros L1 L2 L3 L4 H' H'0 H'1. apply DisjointInclR with (L2 := L2); auto. apply DisjointInclL with (L1 := L1); auto. Qed.
imports: Coq(Arith) Coq(Lexicographic_Exponentiation)