fact: Fixpoint pure_var_bound (M: pure_term) := match M with | pure_var x => 1 + x | pure_app M N => 1 + pure_var_bound M + pure_var_bound N | pure_abs M => 1 + pure_var_bound M end.
imports: List Lia Undecidability.SystemF.SysF Undecidability.SystemF.Autosubst.syntax Undecidability.SystemF.Autosubst.unscoped Undecidability.SystemF.Util.Facts Undecidability.SystemF.Util.poly_type_facts ssreflect ssrbool ssrfun