fact: Fixpoint cll_has_bot_zero_neg f := match f with | cll_var _ => False | cll_cst c => c = cll_bot \/ c = cll_0 | cll_una m f => m = cll_neg \/ cll_has_bot_zero_neg f | cll_bin _ f g => cll_has_bot_zero_neg f \/ cll_has_bot_zero_neg g end.
imports: List Permutation Undecidability.Shared.Libs.DLW(utils) Undecidability.ILL(ILL CLL)