fact: Fixpoint head_of_const (t : term) := match t with | tConst h _ => Some h | tApp s _ => head_of_const s | _ => None end.
imports: Ascii String Undecidability.L(Util.L_facts) MetaCoq(Template.All Template.Checker) Undecidability.Shared.Libs.PSL.Base MetaCoq.Utils.bytestring