YES a__fromXconsmarkXfromsXa__lengthnil0a__lengthconsXYsa__length1Ya__length1Xa__lengthXmarkfromXa__frommarkXmarklengthXa__lengthXmarklength1Xa__length1XmarkconsX1X2consmarkX1X2marksXsmarkXmarknilnilmark00a__fromXfromXa__lengthXlengthXa__length1Xlength1X2.1a__fromXmarkXa__lengthconsXYa__length1Ya__length1Xa__lengthXmarkfromXa__frommarkXmarkfromXmarkXmarklengthXa__lengthXmarklength1Xa__length1XmarkconsX1X2markX1marksXmarkXtruemarkfromXa__frommarkXa__fromXmarkXmarkfromXmarkXmarkconsX1X2markX1marksXmarkXtruefrom14mark14a__from14length10a__length13length111a__length113nil04002mark11from11a__from11mark11cons21s11a__from11length1a__length1length11a__length11nil000markfromXa__frommarkXa__fromXmarkXmarkconsX1X2markX1marksXmarkX1a__from121mark121from1221a__from1221length10a__length10length110a__length110cons211s121nil01000mark121a__fromXmarkXmarksXmarkXa__fromXmarkXfalsemarksXmarkXtruemarksXmarkX1true1marklength1Xa__length1XfalsemarklengthXa__lengthXfalsea__length1Xa__lengthXa__lengthconsXYa__length1Ytruea__lengthconsXYa__length1Y1true1a__length1Xa__lengthX1false1AProVEAProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Statistics for single proof: 100.00 % (11 real / 0 unknown / 0 assumptions / 11 total proof steps)http://aprove.informatik.rwth-aachen.deJohnDoe