fact: Definition isaafield ( A : acommring ) := ( ringunel2 ( X := A ) ) # 0 × forall x : A, x # 0 -> multinvpair A x.
imports: UniMath.Tactics.EnsureStructuredProofs UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.NaturalNumbers UniMath.Algebra.RigsAndRings UniMath.Algebra.Domains_and_Fields UniMath.NumberSystems.Integers UniMath.Algebra.Monoids