fact: Fixpoint df_pred f ν := match f with | df_cst x n => ν x = n | df_eq x y => ν x = ν y | df_op o x y z => ν x = de_op_sem o (ν y) (ν z) | df_bin o f g => df_op_sem o (⟦f⟧ ν) (⟦g⟧ ν) | df_exst f => exists n, ⟦f⟧ n·ν end where "⟦ f ⟧" := (df_pred f).
imports: Arith Nat ZArith Lia Undecidability.Shared.Libs.DLW.Utils(utils_tac gcd sums bounded_quantification)