null
nil
true
null
add
n
x
false
tail
add
n
x
x
tail
nil
nil
head
add
n
x
n
app
nil
y
y
app
add
n
x
y
add
n
app
x
y
reverse
nil
nil
reverse
add
n
x
app
reverse
x
add
n
nil
shuffle
x
shuff
x
nil
shuff
x
y
if
null
x
x
y
app
y
add
head
x
nil
if
true
x
y
z
y
if
false
x
y
z
shuff
reverse
tail
x
z
null
1
nil
0
true
0
add
2
false
0
tail
1
head
1
app
2
reverse
1
shuffle
1
shuff
2
if
4
INNERMOST
./TRS/SchneiderKamp/trs/thiemann03.trs