r
xs
ys
zs
nil
xs
r
xs
nil
zs
cons
w
ws
r
xs
xs
cons
succ
zero
zs
ws
r
xs
cons
y
ys
nil
cons
w
ws
r
xs
xs
cons
succ
zero
nil
ws
r
xs
cons
y
ys
cons
z
zs
cons
w
ws
r
ys
cons
y
ys
zs
cons
succ
zero
cons
w
ws
r
4
nil
0
cons
2
succ
1
zero
0
INNERMOST
./TRS/Thiemann/sizeChange.trs