No vertices:
Is chordal: 1
Fill in:
( )
New graph:
directed: false
vcount: 0
edges: {
}

One vertex:
Is chordal: 1
Fill in:
( )
New graph:
directed: false
vcount: 1
edges: {
}

One vertex, don't calculate anything.

Disconnected graph with loops and multiple edges:
Is chordal: 0
Fill in:
( 3 0 )
New graph:
directed: false
vcount: 6
edges: {
0 1
0 2
0 2
0 2
0 3
1 1
1 3
2 3
3 4
3 4
}

Same graph, don't ask for fill_in vector:
Is chordal: 0
Fill in:
( )
New graph:
directed: false
vcount: 6
edges: {
0 1
0 2
0 2
0 2
0 3
1 1
1 3
2 3
3 4
3 4
}

Same graph, don't ask for fill_in vector or newgraph:
Is chordal: 0
Fill in:
( )

Same graph, own calculation of alpha and its inverse:
Is chordal: 0
Fill in:
( 3 0 )
New graph:
directed: false
vcount: 6
edges: {
0 1
0 2
0 2
0 2
0 3
1 1
1 3
2 3
3 4
3 4
}

Same graph, own calculation of alpha:
Is chordal: 0
Fill in:
( 3 0 )
New graph:
directed: false
vcount: 6
edges: {
0 1
0 2
0 2
0 2
0 3
1 1
1 3
2 3
3 4
3 4
}

Same graph, own calculation of inverse alpha:
Is chordal: 0
Fill in:
( 3 0 )
New graph:
directed: false
vcount: 6
edges: {
0 1
0 2
0 2
0 2
0 3
1 1
1 3
2 3
3 4
3 4
}

Wrong size alpha.
Wrong size alpham1.