Marked_purgeremove=purgeMarked_remove.ifnilzyxpurge(nil)nilpurge(.(x,y)).(x,purge(remove(x,y)))remove(x,nil)nilremove(x,.(y,z))if(=(x,y),remove(x,z),.(y,remove(x,z)))purge(nil)nilpurge(.(x,y)).(x,purge(remove(x,y)))remove(x,nil)nilremove(x,.(y,z))if(=(x,y),remove(x,z),.(y,remove(x,z)))Marked_purge(.(x,y))Marked_purge(remove(x,y))Marked_purge(.(x,y))Marked_remove(x,y)Marked_remove(x,.(y,z))Marked_remove(x,z)Marked_remove(x,.(y,z))Marked_remove(x,z)purge(nil)nilpurge(.(x,y)).(x,purge(remove(x,y)))remove(x,nil)nilremove(x,.(y,z))if(=(x,y),remove(x,z),.(y,remove(x,z)))Marked_purge(.(x,y))Marked_purge(remove(x,y))nil0if0.3230purge20=0remove0Marked_purge20purge(nil)nilpurge(.(x,y)).(x,purge(remove(x,y)))remove(x,nil)nilremove(x,.(y,z))if(=(x,y),remove(x,z),.(y,remove(x,z)))Marked_remove(x,.(y,z))Marked_remove(x,z)Marked_remove(x,.(y,z))Marked_remove(x,z)Marked_remove2Marked_remove(x,.(y,z))Marked_remove(x,z)Marked_remove(x,.(y,z))Marked_remove(x,z)purge(nil)nilpurge(.(x,y)).(x,purge(remove(x,y)))remove(x,nil)nilremove(x,.(y,z))if(=(x,y),remove(x,z),.(y,remove(x,z)))