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
INNERMOST
./TRS/Thiemann/tower.trs