appappmapfnilnilappappmapfappappconsxxsappappconsappfxappappmapfxsappsumappappconsxxsappappplusxappsumxsappsizeappappnodexxsappsappsumappappmapsizexsappappplus0x0appappplusappsxyappsappappplusxyapp2map0nil0cons0sum0plus0size0node0s000FULL./TRS/higher-order/Bird/TreeSize.trs