times
x
y
sum
generate
x
y
generate
x
y
gen
x
y
0
gen
x
y
z
if
ge
z
x
x
y
z
if
true
x
y
z
nil
if
false
x
y
z
cons
y
gen
x
y
s
z
sum
nil
0
sum
cons
0
xs
sum
xs
sum
cons
s
x
xs
s
sum
cons
x
xs
ge
x
0
true
ge
0
s
y
false
ge
s
x
s
y
ge
x
y
2.2
ge
s
x
s
y
ge
x
y
gen
x
y
z
ge
z
x
sum
cons
s
x
xs
sum
cons
x
xs
times
x
y
sum
generate
x
y
gen
x
y
z
if
ge
z
x
x
y
z
sum
cons
0
xs
sum
xs
generate
x
y
gen
x
y
0
times
x
y
generate
x
y
if
false
x
y
z
gen
x
y
s
z
true
times
x
y
generate
x
y
false
generate
x
y
gen
x
y
0
false
if
false
x
y
z
gen
x
y
s
z
gen
x
y
z
if
ge
z
x
x
y
z
true
Failed!
NaTT
certifiable-1.6