fact: Definition rigfun_to_unel_rigaddmonoid {X Y : rig} (f : rigfun X Y) : f (0%rig) = 0%rig := pr2 (pr1 (pr2 f)).
imports: UniMath.Algebra.Groups UniMath.MoreFoundations.Sets UniMath.MoreFoundations.Orders UniMath.Algebra.Monoids