minusxyifgtxyxyiftruexysminuspxyiffalsexy0p00psxxgex0truege0sxfalsegesxsygexygt0yfalsegtsx0truegtsxsygtxydivxyif1gexyxyif1truexyif2gty0xyif1falsexy0if2truexysdivminusxyyif2falsexy0minus2if3gt2true0s1p1false000ge2div2if13if23INNERMOST./AProVE_09_Inductive/divhard.trs