sub
0
0
0
sub
s
x
0
s
x
sub
0
s
x
0
sub
s
x
s
y
sub
x
y
zero
nil
zero2
0
nil
zero
cons
x
xs
zero2
sub
x
x
cons
x
xs
zero2
0
nil
nil
zero2
0
cons
x
xs
cons
sub
x
x
zero
xs
zero2
s
y
nil
zero
nil
zero2
s
y
cons
x
xs
zero
cons
x
xs
sub
2
0
0
s
1
zero
1
nil
0
zero2
2
cons
2
INNERMOST
./AProVE_09_Inductive/zerolist.trs