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 2.2 plus s x y p s x towerIter s x y z towerIter p s x y exp y z p s s x p s x times s x y times p s x y times s x y p s x towerIter s x y z p s x times s x y plus y times p s x y tower x y towerIter x y s 0 exp x s y times x exp x y plus s x y plus p s x y towerIter s x y z exp y z exp x s y exp x y true tower x y towerIter x y s 0 false towerIter s x y z towerIter p s x y exp y z true 2 1 tower 2 0 0 s 1 1 1 1 1 1 2 1 plus 2 0 0 towerIter 3 0 0 exp 2 0 0 p 1 0 0 p 1 0 0 1 1 1 0 0 times 2 0 0 0 0 1 1 times 2 1 0 1 0 1 2 2 0 tower 2 0 0 towerIter 3 1 0 0 plus 2 0 1 1 1 1 1 1 1 1 2 1 0 exp 2 1 1 p s s x s p s x p s 0 0 towerIter s x y z exp y z false exp x s y exp x y true tower 2 0 s 1 1 2 plus 2 0 towerIter 3 0 exp 2 2 0 p 1 0 p 1 1 times 2 0 0 0 5855 times 2 1 2 3 tower 2 0 towerIter 3 0 plus 2 1 2 2 exp 2 1 2 1 exp x s y times x exp x y false times s x y times p s x y true 2 1 tower 2 0 0 s 1 1 1 1 1 1 2 1 plus 2 0 0 towerIter 3 0 0 exp 2 0 0 p 1 0 0 p 1 0 0 1 1 1 0 0 times 2 1 1 0 1 1 0 0 0 0 1 1 times 2 1 0 1 0 1 2 2 0 tower 2 0 0 towerIter 3 1 0 0 plus 2 0 1 1 1 1 1 1 1 1 2 1 24233 exp 2 1 1 p s s x s p s x p s 0 0 times s x y p s x false times s x y plus y times p s x y false plus s x y plus p s x y true 2 1 tower 2 0 0 s 1 1 1 1 1 1 2 1 plus 2 1 0 1 1 1 0 0 towerIter 3 0 0 exp 2 0 0 p 1 0 0 p 1 0 0 1 1 1 0 0 times 2 1 1 0 1 1 0 0 0 0 1 35614 times 2 1 0 1 0 1 2 2 0 tower 2 0 0 towerIter 3 1 0 0 plus 2 0 1 1 1 1 1 1 1 1 2 1 0 exp 2 1 1 p s s x s p s x p s 0 0 towerIter s x y z p s x false plus s x y p s x false p s s x p s x true tower 2 0 s 1 1 2 plus 2 0 towerIter 3 0 exp 2 0 p 1 1 0 p 1 2 times 2 0 0 0 9728 times 2 1 2 3 tower 2 0 towerIter 3 0 plus 2 1 2 1 exp 2 1 2 1 NaTT certifiable-1.6