| ∀ vols0. # vols0 < # vols → true → # to-vtbl(vols0) = # vols0 ⊦ # to-vtbl(vols) = # vols, vols = ∅ |
⊦ vols = vols0 ↔ (∀ v. (v ∈ vols ↔ v ∈ vols0) ∧ vols[v] = vols0[v])
∀ vols0. # vols0 < # vols → true → # to-vtbl(vols0) = # vols0 ⊦ # to-vtbl(vols) = # vols, ∀ v. (v ∈ vols ↔ v ∈ ∅) ∧ vols[v] = (∅)[v]
Used terms: ∅, vols