fact: Definition subgrconstr {X : gr} : ∏ (t : hsubtype X), (λ A : hsubtype X, issubgr A) t → ∑ A : hsubtype X, issubgr A := @make_subgr X.
imports: UniMath.MoreFoundations.Orders UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.Subtypes UniMath.Algebra.BinaryOperations UniMath.Algebra.Monoids