max
nil
0
max
cons
x
nil
x
max
cons
x
cons
y
xs
if1
ge
x
y
x
y
xs
if1
true
x
y
xs
max
cons
x
xs
if1
false
x
y
xs
max
cons
y
xs
del
x
nil
nil
del
x
cons
y
xs
if2
eq
x
y
x
y
xs
if2
true
x
y
xs
xs
if2
false
x
y
xs
cons
y
del
x
xs
eq
0
0
true
eq
0
s
y
false
eq
s
x
0
false
eq
s
x
s
y
eq
x
y
sort
xs
if3
empty
xs
xs
if3
true
xs
nil
if3
false
xs
sort
del
max
xs
xs
empty
nil
true
empty
cons
x
xs
false
ge
x
0
true
ge
0
s
x
false
ge
s
x
s
y
ge
x
y
2.2
if2
false
x
y
xs
del
x
xs
del
x
cons
y
xs
eq
x
y
max
cons
x
cons
y
xs
ge
x
y
if3
false
xs
sort
del
max
xs
xs
if3
false
xs
max
xs
max
cons
x
cons
y
xs
if1
ge
x
y
x
y
xs
if1
true
x
y
xs
max
cons
x
xs
if1
false
x
y
xs
max
cons
y
xs
if3
false
xs
del
max
xs
xs
del
x
cons
y
xs
if2
eq
x
y
x
y
xs
sort
xs
if3
empty
xs
xs
eq
s
x
s
y
eq
x
y
ge
s
x
s
y
ge
x
y
sort
xs
empty
xs
true
sort
xs
if3
empty
xs
xs
if3
false
xs
sort
del
max
xs
xs
true
Failed!
NaTT
certifiable-1.6