| ⟨isbuf := true; ns0 := ?⟩ (ns0 = ns2 ∧ adr = adr2 ∧ m = m2 ∧ nx = nx1 ∧ lpt = lpt2 ∧ ns = ns3 ∧ (isbuf ↔ isbuf0) ∧ err2 = err1), ⟨fail_or_success#(; ; err)⟩ (err = err2), # lpt3 = # avol, # lpt1 = # avol, adr = adr1, adr0 = adr3, lpt = lpt1, lpt0 = lpt3, m = m1, m0 = m3, ns = ns1, ns0 = ns4, awbuf-inv(avol, bleb), synced(avol), avol0 ↓ avol ⊦ ∃ err0. (⌊err0⌋ ∨ err0 = ESUCCESS) ∧ ⟨err := err0; if err = ESUCCESS then {adr1 := adr3; m1 := m3; nx := []; lpt1 := lpt3; ns1 := ns4} else isbuf := true; ns4 := ?⟩ (adr2 = adr1 ∧ m2 = m1 ∧ nx1 = nx ∧ lpt2 = lpt1 ∧ ns3 = ns1), err2 = ESUCCESS, adr2 = adr1 ∧ m2 = m1 ∧ nx1 = nx ∧ lpt2 = lpt1 ∧ ns3 = ns1 |
⟨ns0 := ?⟩ (ns0 = ns2 ∧ adr = adr2 ∧ m = m2 ∧ nx = nx1 ∧ lpt = lpt2 ∧ ns = ns3 ∧ (true ↔ isbuf0) ∧ err2 = err1), ⟨fail_or_success#(; ; err)⟩ (err = err2), # lpt1 = # avol, # lpt3 = # avol, adr = adr1, adr0 = adr3, lpt = lpt1, lpt0 = lpt3, m = m1, m0 = m3, ns = ns1, ns0 = ns4, awbuf-inv(avol, bleb), synced(avol), avol0 ↓ avol ⊦ ∃ err0. (⌊err0⌋ ∨ err0 = ESUCCESS) ∧ ⟨err := err0; if err = ESUCCESS then {adr1 := adr3; m1 := m3; nx := []; lpt1 := lpt3; ns1 := ns4} else isbuf := true; ns4 := ?⟩ (adr2 = adr1 ∧ m2 = m1 ∧ nx1 = nx ∧ lpt2 = lpt1 ∧ ns3 = ns1), err2 = ESUCCESS, adr2 = adr1 ∧ m2 = m1 ∧ nx1 = nx ∧ lpt2 = lpt1 ∧ ns3 = ns1