minusx0xminussxsyminusxyquot0sy0quotsxsysquotminusxysyappnilyyappaddnxyaddnappxyreversenilnilreverseaddnxappreversexaddnnilshufflenilnilshuffleaddnxaddnshufflereversexconcatleafyyconcatconsuvyconsuconcatvyless_leavesxleaffalseless_leavesleafconswztrueless_leavesconsuvconswzless_leavesconcatuvconcatwzminussxsyminusxyquotsxsyquotminusxysyquotsxsyminusxyappaddnxyappxyreverseaddnxappreversexaddnnilreverseaddnxreversexshuffleaddnxshufflereversexshuffleaddnxreversexconcatconsuvyconcatvyless_leavesconsuvconswzless_leavesconcatuvconcatwzless_leavesconsuvconswzconcatuvless_leavesconsuvconswzconcatwztruequotsxsyquotminusxysytrue136101quot211s1111minus211000minusx0xminussxsyminusxyquotsxsyminusxyfalse259minussxsyminusxytrue371minus212s1111shuffleaddnxshufflereversextrue371shuffle111add2112reverse111nil00app21112reversenilnilreverseaddnxappreversexaddnnilappnilyyappaddnxyaddnappxyshuffleaddnxreversexfalse347reverseaddnxreversextrue41reverse111add2112reverseaddnxappreversexaddnnilfalse4appaddnxyappxytrue41app211add2112less_leavesconsuvconswzless_leavesconcatuvconcatwztrue31less_leaves21112cons211112concat21112leaf00concatleafyyconcatconsuvyconsuconcatvyless_leavesconsuvconswzconcatuvfalseless_leavesconsuvconswzconcatwzfalseconcatconsuvyconcatvytrue1concat211cons2112