minus
x
0
x
minus
s
x
s
y
minus
x
y
quot
0
s
y
0
quot
s
x
s
y
s
quot
minus
x
y
s
y
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
nil
nil
shuffle
add
n
x
add
n
shuffle
reverse
x
concat
leaf
y
y
concat
cons
u
v
y
cons
u
concat
v
y
less_leaves
x
leaf
false
less_leaves
leaf
cons
w
z
true
less_leaves
cons
u
v
cons
w
z
less_leaves
concat
u
v
concat
w
z
rand
x
x
rand
x
rand
s
x
true
0
less_leaves
2
app
2
add
2
concat
2
leaf
0
shuffle
1
rand
1
quot
2
nil
0
false
0
s
1
reverse
1
0
0
minus
2
cons
2
FULL