| ⊦ v ∈ vols ∧ m < # vols[v] ∧ vols[v][m] = unmapped ∧ abs(avols, apebs, vols, q) → abs(avols[v, avols[v][m, unmapped]], apebs, vols, q) |
vols[v][m] = unmapped, m < # vols[v], abs(avols, apebs, vols, q), v ∈ vols ⊦ abs(avols[v, avols[v][m, unmapped]], apebs, vols, q)