fact: Definition istrans_subtype_containment {X} {A B C : hsubtype X} (leq_AB : A ⊆ B) (leq_BC : B ⊆ C) : A ⊆ C.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.WellOrderedSets UniMath.OrderTheory.DCPOs.AlternativeDefinitions.Dcpo