| apebs[n] = mkpeb(aehdr, empty, buf, m, false), apebs0 = apebs, avhdr0.valid?, aehdr.valid?, n < # apebs, ubi-io-inv(apebs) ⊦ ∃ avhdr. ¬ avhdr.valid? ∧ ⟨apebs[n].vidhdr := avhdr⟩ (apebs0 = apebs) |
apebs[n] = mkpeb(aehdr, empty, buf, m, false), aehdr.valid?, avhdr0.valid?, n < # apebs, ubi-io-inv(apebs) ⊦ ∃ avhdr. ¬ avhdr.valid? ∧ ⟨apebs1 := apebs[n, apebs[n].vidhdr:= avhdr]⟩ (apebs = apebs1)