a
l
x1
l
a
x1
r
a
a
x1
a
a
r
x1
b
l
x1
b
a
r
x1
r
b
x1
l
b
x1
2.2
r
a
a
x1
a
r
x1
b
l
x1
r
x1
a
l
x1
a
x1
b
l
x1
a
r
x1
r
a
a
x1
r
x1
r
a
a
x1
a
a
r
x1
b
l
x1
b
a
r
x1
true
b
l
x1
b
a
r
x1
true
2
1
a
1
0
1
1
0
1
1
1
b
1
1
1
0
0
1
4
2
r
1
1
1
1
0
1
0
0
l
1
1
2
2
r
1
0
0
a
1
0
0
b
1
1
0
0
0
1
0
0
r
b
x1
l
b
x1
a
l
x1
l
a
x1
b
l
x1
b
a
r
x1
r
a
a
x1
a
a
r
x1
b
l
x1
r
x1
false
r
a
a
x1
r
x1
true
a
1
1
2
b
1
1
1
r
1
5854
l
1
5855
r
1
1
0
a
1
0
b
1
0
r
a
a
x1
a
a
r
x1
false
b
l
x1
a
r
x1
false
r
a
a
x1
a
r
x1
false
a
l
x1
a
x1
true
a
1
1
0
b
1
1
1144
r
1
1144
l
1
1
1
r
1
0
a
1
1
0
b
1
0
NaTT
certifiable-1.6