fact: Record def (i : interval int) := Def { r :> R; #[canonical=no] P : itv_cond i r }.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool) mathcomp(ssrnat eqtype choice order ssralg ssrnum ssrint) mathcomp(interval) mathcomp(mathcomp_extra boolp) signed