quot
0
s
y
s
z
0
quot
s
x
s
y
z
quot
x
y
z
quot
x
0
s
z
s
quot
x
s
z
s
z
2.2
quot
x
0
s
z
quot
x
s
z
s
z
quot
s
x
s
y
z
quot
x
y
z
true
quot
s
x
s
y
z
quot
x
y
z
quot
x
0
s
z
quot
x
s
z
s
z
true
s
1
1
1
0
0
1
quot
3
0
quot
3
1
0
quot
x
0
s
z
quot
x
s
z
s
z
quot
x
0
s
z
quot
x
s
z
s
z
false
NaTT
certifiable-1.6