After step (a):
4 vertices:
(3 5) - degree 2
(5 3) - degree 2
(1 3) - degree 2
(3 1) - degree 2
4 edges:
[3 5 5 3]
[3 1 1 3]
[5 3 3 1]
[1 3 3 5]
2 faces:
Unbounded face.
    Hole #1: (3 5)   [3 5 5 3]   (5 3)   [5 3 3 1]   (3 1)   [3 1 1 3]   (1 3)   [1 3 3 5]   (3 5)
Outer boundary: (3 5)   [1 3 3 5]   (1 3)   [3 1 1 3]   (3 1)   [5 3 3 1]   (5 3)   [3 5 5 3]   (3 5)

After step (b):
6 vertices:
(3 5) - degree 2
(5 3) - degree 2
(1 3) - degree 2
(3 1) - degree 2
(4 4) - degree 3
(2 2) - degree 3
7 edges:
[3 5 4 4]
[3 1 2 2]
[5 3 3 1]
[1 3 3 5]
[4 4 5 3]
[2 2 1 3]
[4 4 2 2]
3 faces:
Unbounded face.
    Hole #1: (3 5)   [3 5 4 4]   (4 4)   [4 4 5 3]   (5 3)   [5 3 3 1]   (3 1)   [3 1 2 2]   (2 2)   [2 2 1 3]   (1 3)   [1 3 3 5]   (3 5)
Outer boundary: (2 2)   [4 4 2 2]   (4 4)   [3 5 4 4]   (3 5)   [1 3 3 5]   (1 3)   [2 2 1 3]   (2 2)
Outer boundary: (4 4)   [4 4 2 2]   (2 2)   [3 1 2 2]   (3 1)   [5 3 3 1]   (5 3)   [4 4 5 3]   (4 4)

After step (c):
4 vertices:
(3 5) - degree 2
(5 3) - degree 2
(1 3) - degree 2
(3 1) - degree 2
4 edges:
[3 5 5 3]
[3 1 1 3]
[5 3 3 1]
[1 3 3 5]
2 faces:
Unbounded face.
    Hole #1: (3 5)   [3 5 5 3]   (5 3)   [5 3 3 1]   (3 1)   [3 1 1 3]   (1 3)   [1 3 3 5]   (3 5)
Outer boundary: (5 3)   [3 5 5 3]   (3 5)   [1 3 3 5]   (1 3)   [3 1 1 3]   (3 1)   [5 3 3 1]   (5 3)
