| ⊦ (∀ a0. count(a0, bag0 ++ a) ≤ count(a0, bag1 ++ a)) ↔ (∀ a. count(a, bag0) ≤ count(a, bag1)) |
∀ a0. count(a0, bag0 ++ a) ≤ count(a0, bag1 ++ a) ⊦ ∀ a. count(a, bag0) ≤ count(a, bag1)
∀ a. count(a, bag0) ≤ count(a, bag1) ⊦ ∀ a0. count(a0, bag0 ++ a) ≤ count(a0, bag1 ++ a)