| ⊦ st1 = st2 ↔ (∀ a. (a ∈ st1 ↔ a ∈ st2) ∧ lookup(a, st1) = lookup(a, st2)) |
⊦ st1 = st2 ↔ (∀ a. (a ∈ st1 ↔ a ∈ st2) ∧ st1[a] = st2[a])
⊦ (∀ a. (a ∈ st1 ↔ a ∈ st2) ∧ st1[a] = st2[a]) ↔ (∀ a. (a ∈ st1 ↔ a ∈ st2) ∧ lookup(a, st1) = lookup(a, st2))
Used terms: st2, st1