| count(A[n0], mkbag(A, i) -- A[n]) - (count(A[n0], mkbag(A, i) -- A[n]) = 0 ⊃ 0;1) = 0, A[m] = A[n0], A[n0] = A[n], n0 < # A, n < # A, m < # A, n0 < i, n < i, m < i, i ≤ # A ⊦ n = m, n = n0, n0 = m |
count(A[n], mkbag(A, i)) - (count(A[n], mkbag(A, i)) = 0 ⊃ 0;1) - (count(A[n], mkbag(A, i)) - (count(A[n], mkbag(A, i)) = 0 ⊃ 0;1) = 0 ⊃ 0;1) = 0, A[m] = A[n], A[n0] = A[n], n0 < # A, n < # A, m < # A, n0 < i, n < i, m < i, i ≤ # A ⊦ n = m, n = n0, n0 = m
Used simplifier rules: count-del-same: ⊦ count(a, bag -- a) = count(a, bag) - (count(a, bag) = 0 ⊃ 0;1);