fact: Fixpoint subterm ts1 ts2 := match ts1 with Pts n _ :: tsx1 => if has (key n) ts2 then subterm tsx1 (kfree n ts2) else false | Var n :: tsx1 => if has (var n) ts2 then subterm tsx1 (vfree n ts2) else false | [::] => true end.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq) pcm(options pred prelude) pcm(pcm unionmap natmap)