| ∀ n. (∀ n0. count(n0, (bag0 -- n) ++ n) = count(n0, bag0)) ↔ count(n, bag0) ≠ 0 ⊦ 0 + count(n0, bag0 -- n) = count(n0, bag0), count(n, bag0) = 0, n = m, n0 = m, n0 = n |
∀ n. (∀ n0. count(n0, (bag0 -- n) ++ n) = count(n0, bag0)) ↔ count(n, bag0) ≠ 0 ⊦ count(n, bag0) = 0, count(n0, bag0 -- n) = count(n0, bag0), n = m, n0 = n, n0 = m
Used simplifier rules: c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ n + 0 = n; (s)