proposition: Lemma stn_inhabited_implies_succ {n:nat} (i : ⟦ n ⟧%stn) : ∑ m, n = S m.
proof: Proof. destruct n as [| m]. - destruct i as [i le_i_0]. destruct (negnatlthn0 _ le_i_0). - exists m. apply idpath. Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.Maybe UniMath.Combinatorics.StandardFiniteSets UniMath.Algebra.Domains_and_Fields UniMath.Algebra.RigsAndRings