fib
N
sel
N
fib1
s
0
s
0
fib1
X
Y
cons
X
fib1
Y
add
X
Y
add
0
X
X
add
s
X
Y
s
add
X
Y
sel
0
cons
X
XS
X
sel
s
N
cons
X
XS
sel
N
XS
2.2
fib1
X
Y
add
X
Y
add
s
X
Y
add
X
Y
fib
N
fib1
s
0
s
0
sel
s
N
cons
X
XS
sel
N
XS
fib1
X
Y
fib1
Y
add
X
Y
fib
N
sel
N
fib1
s
0
s
0
true
fib
N
sel
N
fib1
s
0
s
0
false
sel
s
N
cons
X
XS
sel
N
XS
true
s
1
1
fib1
2
0
fib1
2
0
fib
1
0
0
0
0
sel
2
2
0
sel
2
0
cons
2
2
1
add
2
0
add
2
0
fib
1
0
fib
N
fib1
s
0
s
0
false
fib1
X
Y
fib1
Y
add
X
Y
true
Failed!
NaTT
certifiable-1.6