| # lpt = # avol, avol[n0] = mapped(buf0), n0 < # avol, awbuf-inv(avol, buffered(n0)), synced(avol0), avol0 ↓ avol, # buf0 + n ≤ LEB_SIZE, n ≤ # buf ⊦ ⟨if isbuf then err := EROFS else {fail_or_success#(; ; err); let m = buffered(n0).leb in if err = ESUCCESS then avol[m] := mapped(avol[m].data + subarray(buf, 0, n)) else { choose n1 with n1 ≠ 0 ∧ n1 < n ∧ is-aligned(# avol[m].data + n1, EB_PAGE_SIZE) in avol[m] := mapped(avol[m].data + subarray(buf, 0, n1)) ifnone skip or skip; isbuf := true}}⟩ (avol0 ↓ avol) |
# lpt = # avol, avol[n0] = mapped(buf0), isbuf, n0 < # avol, awbuf-inv(avol, buffered(n0)), synced(avol0), avol0 ↓ avol, n ≤ # buf, # buf0 + n ≤ LEB_SIZE ⊦ ⟨err := EROFS⟩ (avol0 ↓ avol)
# lpt = # avol, avol[n0] = mapped(buf0), ¬ isbuf, n0 < # avol, awbuf-inv(avol, buffered(n0)), synced(avol0), avol0 ↓ avol, n ≤ # buf, # buf0 + n ≤ LEB_SIZE ⊦ ⟨fail_or_success#(; ; err); let m = buffered(n0).leb in if err = ESUCCESS then avol[m] := mapped(avol[m].data + subarray(buf, 0, n)) else { choose n1 with n1 ≠ 0 ∧ n1 < n ∧ is-aligned(# avol[m].data + n1, EB_PAGE_SIZE) in avol[m] := mapped(avol[m].data + subarray(buf, 0, n1)) ifnone skip or skip; isbuf := true}⟩ (avol0 ↓ avol)