proposition: Lemma isdecrelhzeqminusplus' (i j : hz) : isdecrelhzeq (i - j + j) i = ii1 (hzrminusplus i j).
proof: Proof. induction (isdecrelhzeq (i - j + j) i) as [T | F]. - apply maponpaths. apply isasethz. - apply fromempty. apply F. apply (hzrminusplus i j). Qed.
imports: UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.PartA UniMath.MoreFoundations.NegativePropositions UniMath.Algebra.Monoids UniMath.Algebra.Groups UniMath.Algebra.RigsAndRings UniMath.NumberSystems.NaturalNumbersAlgebra