proposition: Lemma ge0 x : unify_r >=0 cond -> x0 <= x%:num :> T.
proof: Proof. by case: x => [x /= /andP[]]; move: cond nz => [[[]|]|] [] //= _ /eqP ->. Qed.
imports: HB(structures) Coq(ssreflect ssrfun ssrbool) mathcomp(ssrnat eqtype choice order ssralg ssrnum ssrint) mathcomp(mathcomp_extra)