| ∀ n. (bag0 -- n) ++ n = (n ∈ bag0 ⊃ bag0;bag0 ++ n) ⊦ (m = n ⊃ bag0;(bag0 -- n) ++ m) ++ n = (n ∈ bag0 ++ m ⊃ bag0 ++ m;bag0 ++ m ++ n) |
∀ n. (bag0 -- n) ++ n = (n ∈ bag0 ⊃ bag0;bag0 ++ n) ⊦ (bag0 -- n) ++ m ++ n = (n ∈ bag0 ++ m ⊃ bag0 ++ m;bag0 ++ m ++ n), m = n
Used simplifier rules: ⊦ n ∈ bag0 ++ n; (s)% ⊦ bag ++ n = bag2 ++ n ↔ bag = bag2; (s)