YES a__first0Xnila__firstsXconsYZconsmarkYfirstXZa__fromXconsmarkXfromsXmarkfirstX1X2a__firstmarkX1markX2markfromXa__frommarkXmark00marknilnilmarksXsmarkXmarkconsX1X2consmarkX1X2a__firstX1X2firstX1X2a__fromXfromX2.1a__firstsXconsYZmarkYa__fromXmarkXmarkfirstX1X2a__firstmarkX1markX2markfirstX1X2markX1markfirstX1X2markX2markfromXa__frommarkXmarkfromXmarkXmarksXmarkXmarkconsX1X2markX1true1a__first2-112a__from11mark121first22122a__first22122from1221a__from1221001nil00s1121cons211mark11a__fromXmarkXmarkfirstX1X2a__firstmarkX1markX2markfirstX1X2markX1markfirstX1X2markX2a__fromXmarkXfalsemarkfirstX1X2markX2markfirstX1X2markX1truemarkfirstX1X2markX21true1markfirstX1X2markX11true1markfirstX1X2a__firstmarkX1markX2falseAProVEAProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Statistics for single proof: 100.00 % (6 real / 0 unknown / 0 assumptions / 6 total proof steps)http://aprove.informatik.rwth-aachen.deJohnDoe