| ⊦ (∃ n0. eq-entry(n0, lref) ∈ q ∨ eq-entry(n0, lref) = eq-entry(n, lref0)) ↔ lref = lref0, ∃ n. eq-entry(n, lref) ∈ q |
∃ n0. eq-entry(n0, lref) ∈ q ∨ eq-entry(n0, lref) = eq-entry(n, lref0) ⊦ lref = lref0, ∃ n. eq-entry(n, lref) ∈ q
lref = lref0 ⊦ ∃ n. eq-entry(n, lref) ∈ q, ∃ n0. eq-entry(n0, lref) ∈ q ∨ eq-entry(n0, lref) = eq-entry(n, lref0)