LISA Alan01 "" (* Allowed because it uses weak fences on 3 threads. *) { ok=1; } P0 | P1 | P2 ; w[once] x 2 | w[once] y 2 | r[once] r0 z ; f[wmb] | f[wmb] | mov r1 (neq r0 1); w[once] y 1 | w[once] z 1 | b[] r1 Fail ; | | w[once] x 1 ; | | b[] Exit ; | |Fail: ; | | w[once] ok 0 ; | |Exit: ; Observed y=2; x=2; ok=1; 2:r0=1;