| ⊦ (count(a0, bag1) ≤ count(a0, bag0 ++ a) ⊃ count(a0, bag0 ++ a) - count(a0, bag1);0) = count(a0, (bag0 \ bag1) ++ a), a ∈ bag1 |
⊦ a ∈ bag ↔ count(a, bag) ≠ 0
⊦ (count(a0, bag1) ≤ count(a0, bag0 ++ a) ⊃ count(a0, bag0 ++ a) - count(a0, bag1);0) = count(a0, (bag0 \ bag1) ++ a), count(a, bag1) ≠ 0
Used terms: bag1, a