a__f
a
X
X
a__f
X
a__b
b
a__b
a
mark
f
X1
X2
X3
a__f
X1
mark
X2
X3
mark
b
a__b
mark
a
a
a__f
X1
X2
X3
f
X1
X2
X3
a__b
b
2.2
mark
f
X1
X2
X3
mark
X2
mark
b
a__b
a__f
a
X
X
a__f
X
a__b
b
mark
f
X1
X2
X3
a__f
X1
mark
X2
X3
a__f
a
X
X
a__b
true
mark
f
X1
X2
X3
mark
X2
true
a
0
0
b
0
0
a__b
0
0
a__f
3
0
a__b
0
0
f
3
2
1
mark
1
1
0
mark
1
0
a__f
3
0
mark
f
X1
X2
X3
a__f
X1
mark
X2
X3
false
a__f
a
X
X
a__f
X
a__b
b
true
a
0
3
b
0
2
a__b
0
1
a__f
3
0
a__b
0
0
f
3
1
mark
1
0
mark
1
0
a__f
3
1
3
0
a__f
a
X
X
a__b
false
mark
b
a__b
false
NaTT
certifiable-1.6