| a ∈ st1, ∀ a. a ∈ st1 → a ∈ st2 ∧ lookup(a, st1) = lookup(a, st2) ⊦ a ∈ st2 ∧ lookup(a, st1) = lookup(a, st2) |
a ∈ st1, ∀ a. a ∈ st1 → a ∈ st2 ∧ lookup(a, st1) = lookup(a, st2) ⊦ a ∈ st2
a ∈ st1, ∀ a. a ∈ st1 → a ∈ st2 ∧ lookup(a, st1) = lookup(a, st2) ⊦ lookup(a, st1) = lookup(a, st2)