lessElements
l
t
lessE
l
t
0
lessE
l
t
n
if
le
length
l
n
le
length
toList
t
n
l
t
n
if
true
b
l
t
n
l
if
false
true
l
t
n
t
if
false
false
l
t
n
lessE
l
t
s
n
length
nil
0
length
cons
n
l
s
length
l
toList
leaf
nil
toList
node
t1
n
t2
append
toList
t1
cons
n
toList
t2
append
nil
l2
l2
append
cons
n
l1
l2
cons
n
append
l1
l2
le
s
n
0
false
le
0
m
true
le
s
n
s
m
le
n
m
a
c
a
d
2.2
lessE
l
t
n
le
length
l
n
lessE
l
t
n
toList
t
if
false
false
l
t
n
lessE
l
t
s
n
toList
node
t1
n
t2
toList
t2
le
s
n
s
m
le
n
m
length
cons
n
l
length
l
lessElements
l
t
lessE
l
t
0
toList
node
t1
n
t2
append
toList
t1
cons
n
toList
t2
append
cons
n
l1
l2
append
l1
l2
lessE
l
t
n
length
toList
t
lessE
l
t
n
length
l
lessE
l
t
n
if
le
length
l
n
le
length
toList
t
n
l
t
n
toList
node
t1
n
t2
toList
t1
lessE
l
t
n
le
length
toList
t
n
true
lessElements
l
t
lessE
l
t
0
false
lessE
l
t
n
if
le
length
l
n
le
length
toList
t
n
l
t
n
if
false
false
l
t
n
lessE
l
t
s
n
true
Failed!
NaTT
certifiable-1.6