| # apebs = # wlar, # wlar0 = # apebs, apebs[n] = mkpeb(aehdr, avhdr, buf, m, boolvar), n0 = recs[ladr].pnum, q0 = q1, recs = recs1, recs2 = recs0 -- (VTBL_VOLID × VTBL_LNUM), vtblpnum = n, bflipset-cons(bflipset, wlar), bflipset-cons(bflipset0, wlar0), unique-sqns(apebs), unmapped-vols(vols0), valid-eraseq(wlar, q), valid-eraseq(wlar0, q1), valid-eraseq-stronger(apebs, q1), valid-recs(apebs, wlar0, recs0), valid-vtbl(apebs, vols, wlar, vtblpnum), valid-vtbl(apebs, vols0, wlar0, n), valid-wl(apebs, wlar), valid-wl(apebs, wlar0), ladr.vol ∈ vols, ladr ∈ recs, q1 ⊆ q, recs ⊥ vols, ∀ v, m, n. v × m ∈ recs ∧ recs[v × m].pnum = n ∨ v ∈ vols ∧ m < # vols[v] ∧ vols[v][m] = ⌜n⌝ ↔ wlar[n].status = used ∧ n < # apebs ∧ apebs[n].vidhdr.valid? ∧ apebs[n].vidhdr.vol = v ∧ apebs[n].vidhdr.leb = m ∧ n ≠ vtblpnum, ∃ vtbl. is-encoded(vtbl, apebs[vtblpnum].data) ∧ valid-eraseq-strong(apebs, vtbl, q) ⊦ recs = ∅, VTBL_VOLID ∈ vols, VTBL_VOLID × VTBL_LNUM ∈ recs, VTBL_VOLID ∈ vols0, n ∈ q1, ladr.vol ∈ vols |