plus 0 x x plus s x y s plus p s x y times 0 y 0 times s x y plus y times p s x y exp x 0 s 0 exp x s y times x exp x y p s 0 0 p s s x s p s x tower x y towerIter x y s 0 towerIter 0 y z z towerIter s x y z towerIter p s x y exp y z plus 2 0 0 s 1 p 1 times 2 exp 2 tower 2 towerIter 3 FULL ./TRS/Thiemann/tower.trs