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
2.2
add
s
X
Y
add
X
Y
sqr
s
X
dbl
X
terms
N
sqr
N
sqr
s
X
sqr
X
dbl
s
X
dbl
X
first
s
X
cons
Y
Z
first
X
Z
terms
N
terms
s
N
sqr
s
X
add
sqr
X
dbl
X
true
terms
N
terms
s
N
true
Failed!
NaTT
certifiable-1.6