ocr: Start A Success Raise Priority Restore Priority B Failure Use SF L1 No Create exists? L1 Delete L1 (Tc-T1)> No Ret(0) Delta? Yes Failure Create (Tc-T2)> Yes L2 Delta? Success No Delete L2 Delete L1 A A A Failure Success Restore Priority B Ret(-1) Figure 1. An llustration of Algorithm W
