terms
N
cons
recip
sqr
N
terms
s
N
sqr
0
0
sqr
s
X
s
add
sqr
X
dbl
X
dbl
0
0
dbl
s
X
s
s
dbl
X
add
0
X
X
add
s
X
Y
s
add
X
Y
first
0
X
nil
first
s
X
cons
Y
Z
cons
Y
first
X
Z
half
0
0
half
s
0
0
half
s
s
X
s
half
X
half
dbl
X
X
2.2
half
s
s
X
half
X
sqr
s
X
sqr
X
terms
N
terms
s
N
sqr
s
X
dbl
X
sqr
s
X
add
sqr
X
dbl
X
add
s
X
Y
add
X
Y
first
s
X
cons
Y
Z
first
X
Z
terms
N
sqr
N
dbl
s
X
dbl
X
true
first
s
X
cons
Y
Z
first
X
Z
true
s
1
1
recip
1
0
dbl
1
0
dbl
1
0
terms
1
0
half
1
0
half
1
0
sqr
1
0
0
0
0
first
2
2
0
nil
0
0
first
2
0
cons
2
2
1
add
2
0
add
2
0
sqr
1
0
terms
1
0
terms
N
terms
s
N
true
Failed!
NaTT
certifiable-1.6