fact: Definition isdecrigtoringrel (X : rig) {R : hrel X} (is : @isbinophrel (rigaddabmonoid X) R) (is' : @isinvbinophrel (rigaddabmonoid X) R) (isd : isdecrel R) : isdecrel (rigtoringrel X is).
imports: UniMath.Algebra.Groups UniMath.MoreFoundations.Sets UniMath.MoreFoundations.Orders UniMath.Algebra.Monoids