| ⊦ ¬(∀ a0. count(a0, bag0 ++ a ++ b) = count(a0, bag1 ++ a)) ↔ bag0 ++ b ≠ bag1 |
∀ a0. (a0 = b ⊃ 1;0) + count(a0, bag0) = count(a0, bag1) ⊦ bag0 ++ b = bag1
Used simplifier rules: count-insert: ⊦ count(a, bag ++ b) = (a = b ⊃ 1;0) + count(a, bag);%c: ⊦ m + n = n + m; from specification nat-basic2%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%eq-01: ⊦ m + n = m + n0 ↔ n = n0; from specification nat-basic2