proposition: Lemma isdecrelhzeqminusplus (i j : hz) : isdecrelhzeq i (i - j + j) = ii1 (hzrminusplus' i j).
proof: Proof. induction (isdecrelhzeq i (i - j + j)) 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