new version -- this may fix perf bugs
new version -- this may fix perf bugs

tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc