fact: Definition finite_t_dec_choice X Y (R : X -> Y -> Prop) : finite_t Y -> (forall x y, { R x y } + { ~ R x y }) -> (forall x, ex (R x)) -> { f | forall x, R x (f x) }.
imports: List Arith Lia Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_nat fin_base) Undecidability.Shared.Libs.DLW.Vec(pos vec)