perfectpMarked_<=trueMarked_perfectpfalseMarked_f0ifMarked_ifsMarked_-<=f-uzyx-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_-(s(x),s(y))Marked_-(x,y)Marked_<=(s(x),s(y))Marked_<=(x,y)Marked_perfectp(s(x))Marked_f(x,s(0),s(x),s(x))Marked_f(s(x),0,z,u)Marked_f(x,u,-(z,s(x)),u)Marked_f(s(x),0,z,u)Marked_-(z,s(x))Marked_f(s(x),s(y),z,u)Marked_if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_f(s(x),s(y),z,u)Marked_<=(x,y)Marked_f(s(x),s(y),z,u)Marked_f(s(x),-(y,x),z,u)Marked_f(s(x),s(y),z,u)Marked_-(y,x)Marked_f(s(x),s(y),z,u)Marked_f(x,u,z,u)-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_f(s(x),0,z,u)Marked_f(x,u,-(z,s(x)),u)Marked_f(s(x),s(y),z,u)Marked_f(s(x),-(y,x),z,u)Marked_f(s(x),s(y),z,u)Marked_f(x,u,z,u)Marked_f1Marked_f(s(x),s(y),z,u)Marked_f(x,u,z,u)Marked_f(s(x),0,z,u)Marked_f(x,u,-(z,s(x)),u)-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_f(s(x),s(y),z,u)Marked_f(s(x),-(y,x),z,u)-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_f(s(x),s(y),z,u)Marked_f(s(x),-(y,x),z,u)-10f0<=10s220if220030Marked_f30false0true0perfectp20-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_<=(s(x),s(y))Marked_<=(x,y)Marked_<=1Marked_<=(s(x),s(y))Marked_<=(x,y)-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))Marked_-(s(x),s(y))Marked_-(x,y)Marked_-1Marked_-(s(x),s(y))Marked_-(x,y)-(x,0)x-(s(x),s(y))-(x,y)<=(0,y)true<=(s(x),0)false<=(s(x),s(y))<=(x,y)if(true,x,y)xif(false,x,y)yperfectp(0)falseperfectp(s(x))f(x,s(0),s(x),s(x))f(0,y,0,u)truef(0,y,s(z),u)falsef(s(x),0,z,u)f(x,u,-(z,s(x)),u)f(s(x),s(y),z,u)if(<=(x,y),f(s(x),-(y,x),z,u),f(x,u,z,u))