| A[m0] = A[m], A[m1] = A[m], m1 < i, m < i, m0 < i, m1 < # A, m < # A, m0 < # A, i ≤ # A, count(A[m], mkbag(A, i)) ≤ 2 ⊦ m = m0, m = m1, m0 = m1 |
⊦ m ≤ n → (n ≤ m ↔ m = n)
A[m1] = A[m], A[m0] = A[m], m0 < # A, m < # A, m1 < # A, m0 < i, m < i, m1 < i, count(A[m], mkbag(A, i)) ≤ 2, i ≤ # A ⊦ m = m1, m = m0, m0 = m1, 2 ≤ count(A[m], mkbag(A, i))
2 = count(A[m], mkbag(A, i)), A[m1] = A[m], A[m0] = A[m], m0 < # A, m < # A, m1 < # A, m0 < i, m < i, m1 < i, i ≤ # A, 2 ≤ count(A[m], mkbag(A, i)) ⊦ m = m1, m = m0, m0 = m1
Used terms: 2, count(A[m], mkbag(A, i))