ifMarked_ptruefalseMarked_minuspminusMarked_lesleMarked_if0yxp(0)0p(s(x))xle(0,y)truele(s(x),0)falsele(s(x),s(y))le(x,y)minus(x,0)xminus(x,s(y))if(le(x,s(y)),0,p(minus(x,p(s(y)))))if(true,x,y)xif(false,x,y)yp(0)0p(s(x))xle(0,y)truele(s(x),0)falsele(s(x),s(y))le(x,y)minus(x,0)xminus(x,s(y))if(le(x,s(y)),0,p(minus(x,p(s(y)))))if(true,x,y)xif(false,x,y)yMarked_le(s(x),s(y))Marked_le(x,y)Marked_minus(x,s(y))Marked_if(le(x,s(y)),0,p(minus(x,p(s(y)))))Marked_minus(x,s(y))Marked_le(x,s(y))Marked_minus(x,s(y))Marked_p(minus(x,p(s(y))))Marked_minus(x,s(y))Marked_minus(x,p(s(y)))Marked_minus(x,s(y))Marked_p(s(y))p(0)0p(s(x))xle(0,y)truele(s(x),0)falsele(s(x),s(y))le(x,y)minus(x,0)xminus(x,s(y))if(le(x,s(y)),0,p(minus(x,p(s(y)))))if(true,x,y)xif(false,x,y)yMarked_minus(x,s(y))Marked_minus(x,p(s(y)))0000000000000000000le000000000000000000000000000000000000s001000000101101101000000000minus000000000111010001000000000000000000p000000000111000000000000000Marked_minus000000000000000000000000100000000000false000000000000000000true000000000000000000if000000000000000000100010001100010001000000000p(0)0p(s(x))xle(0,y)truele(s(x),0)falsele(s(x),s(y))le(x,y)minus(x,0)xminus(x,s(y))if(le(x,s(y)),0,p(minus(x,p(s(y)))))if(true,x,y)xif(false,x,y)yMarked_le(s(x),s(y))Marked_le(x,y)00le0s110Marked_le10minus10p10false0true0if110