active
zeros
mark
cons
0
zeros
active
U11
tt
L
mark
s
length
L
active
and
tt
X
mark
X
active
isNat
0
mark
tt
active
isNat
length
V1
mark
isNatList
V1
active
isNat
s
V1
mark
isNat
V1
active
isNatIList
V
mark
isNatList
V
active
isNatIList
zeros
mark
tt
active
isNatIList
cons
V1
V2
mark
and
isNat
V1
isNatIList
V2
active
isNatList
nil
mark
tt
active
isNatList
cons
V1
V2
mark
and
isNat
V1
isNatList
V2
active
length
nil
mark
0
active
length
cons
N
L
mark
U11
and
isNatList
L
isNat
N
L
active
cons
X1
X2
cons
active
X1
X2
active
U11
X1
X2
U11
active
X1
X2
active
s
X
s
active
X
active
length
X
length
active
X
active
and
X1
X2
and
active
X1
X2
cons
mark
X1
X2
mark
cons
X1
X2
U11
mark
X1
X2
mark
U11
X1
X2
s
mark
X
mark
s
X
length
mark
X
mark
length
X
and
mark
X1
X2
mark
and
X1
X2
proper
zeros
ok
zeros
proper
cons
X1
X2
cons
proper
X1
proper
X2
proper
0
ok
0
proper
U11
X1
X2
U11
proper
X1
proper
X2
proper
tt
ok
tt
proper
s
X
s
proper
X
proper
length
X
length
proper
X
proper
and
X1
X2
and
proper
X1
proper
X2
proper
isNat
X
isNat
proper
X
proper
isNatList
X
isNatList
proper
X
proper
isNatIList
X
isNatIList
proper
X
proper
nil
ok
nil
cons
ok
X1
ok
X2
ok
cons
X1
X2
U11
ok
X1
ok
X2
ok
U11
X1
X2
s
ok
X
ok
s
X
length
ok
X
ok
length
X
and
ok
X1
ok
X2
ok
and
X1
X2
isNat
ok
X
ok
isNat
X
isNatList
ok
X
ok
isNatList
X
isNatIList
ok
X
ok
isNatIList
X
top
mark
X
top
proper
X
top
ok
X
top
active
X
2.2
active
U11
tt
L
length
L
length
mark
X
length
X
active
cons
X1
X2
active
X1
U11
mark
X1
X2
U11
X1
X2
proper
U11
X1
X2
U11
proper
X1
proper
X2
top
mark
X
proper
X
top
mark
X
top
proper
X
length
ok
X
length
X
proper
U11
X1
X2
proper
X1
cons
mark
X1
X2
cons
X1
X2
proper
U11
X1
X2
proper
X2
active
zeros
cons
0
zeros
active
and
X1
X2
and
active
X1
X2
proper
isNatList
X
isNatList
proper
X
isNatList
ok
X
isNatList
X
active
U11
X1
X2
U11
active
X1
X2
s
mark
X
s
X
active
isNat
length
V1
isNatList
V1
proper
isNat
X
isNat
proper
X
active
length
cons
N
L
and
isNatList
L
isNat
N
s
ok
X
s
X
and
ok
X1
ok
X2
and
X1
X2
active
s
X
active
X
top
ok
X
active
X
top
ok
X
top
active
X
proper
isNatIList
X
proper
X
active
length
cons
N
L
U11
and
isNatList
L
isNat
N
L
proper
length
X
proper
X
active
s
X
s
active
X
active
length
cons
N
L
isNatList
L
active
and
X1
X2
active
X1
proper
length
X
length
proper
X
proper
isNat
X
proper
X
active
length
X
length
active
X
proper
and
X1
X2
and
proper
X1
proper
X2
active
isNatList
cons
V1
V2
isNat
V1
isNat
ok
X
isNat
X
proper
isNatList
X
proper
X
active
isNat
s
V1
isNat
V1
proper
cons
X1
X2
proper
X1
proper
s
X
proper
X
proper
isNatIList
X
isNatIList
proper
X
active
cons
X1
X2
cons
active
X1
X2
and
mark
X1
X2
and
X1
X2
proper
cons
X1
X2
proper
X2
proper
and
X1
X2
proper
X2
active
U11
X1
X2
active
X1
active
isNatIList
cons
V1
V2
isNat
V1
proper
cons
X1
X2
cons
proper
X1
proper
X2
active
isNatList
cons
V1
V2
and
isNat
V1
isNatList
V2
proper
and
X1
X2
proper
X1
active
isNatIList
V
isNatList
V
active
isNatList
cons
V1
V2
isNatList
V2
active
isNatIList
cons
V1
V2
and
isNat
V1
isNatIList
V2
isNatIList
ok
X
isNatIList
X
active
U11
tt
L
s
length
L
cons
ok
X1
ok
X2
cons
X1
X2
U11
ok
X1
ok
X2
U11
X1
X2
active
length
cons
N
L
isNat
N
proper
s
X
s
proper
X
active
length
X
active
X
active
isNatIList
cons
V1
V2
isNatIList
V2
true
top
ok
X
top
active
X
top
mark
X
top
proper
X
true
Failed!
NaTT
certifiable-1.6