--------------------
0. EXAMINING:
1 | ['Mc']
2 | ['Y', 'M', 'P']
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

SINGLETON-PROP-ON-VAR('1')
0. CONTINUE:
1 | ['Mc']
2 | ['Y', 'M', 'P']
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

--------------------
1. EXAMINING:
1 | Mc*
2 | ['Y', 'M', 'P']
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

1. CONTINUE:
1 | Mc*
2 | ['Y', 'M', 'P']
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

--------------------
2. EXAMINING:
1 | Mc*
2 | Y*
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 3) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(3):
1 | Mc*
2 | Y*
3 | ['M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | ['M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | ['M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | ['M', 'O', 'B']
4 | ['M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

2. CONTINUE:
1 | Mc*
2 | Y*
3 | ['M', 'O', 'B']
4 | ['M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

--------------------
3. EXAMINING:
1 | Mc*
2 | Y*
3 | M*
4 | ['M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | ['M', 'O', 'B']
6 | ['P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | ['O', 'B']
6 | ['P']

SINGLETON-PROP-ON-VAR('6')
CONSTRAINT-FAILS: BinaryConstraint(6, 5) : McCain, Palin can't be next to Obama, Biden
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | ['B']
6 | ['P']

CONSTRAINT-FAILS: BinaryConstraint(6, 5) : McCain, Palin can't be next to Obama, Biden
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | []
6 | ['P']

3. FAIL:
1 | Mc*
2 | Y*
3 | M*
4 | ['O', 'B']
5 | []
6 | ['P']

--------------------
4. EXAMINING:
1 | Mc*
2 | Y*
3 | O*
4 | ['M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | O*
4 | ['M', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : Obama, Biden must be next to each-other
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | O*
4 | ['M', 'B']
5 | ['M', 'O']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | O*
4 | ['M', 'B']
5 | ['M']
6 | ['M', 'P']

SINGLETON-PROP-ON-VAR('5')
CONSTRAINT-FAILS: BinaryConstraint(5, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | O*
4 | ['B']
5 | ['M']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(5, 6) : Moose can't be next to Palin
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | O*
4 | ['B']
5 | ['M']
6 | ['M']

CONSTRAINT-FAILS: BinaryConstraint(5, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | O*
4 | ['B']
5 | ['M']
6 | []

4. FAIL:
1 | Mc*
2 | Y*
3 | O*
4 | ['B']
5 | ['M']
6 | []

--------------------
5. EXAMINING:
1 | Mc*
2 | Y*
3 | B*
4 | ['M', 'O', 'B']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | B*
4 | ['M', 'O']
5 | ['M', 'O', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : Obama, Biden must be next to each-other
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | B*
4 | ['M', 'O']
5 | ['M', 'B']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | Y*
3 | B*
4 | ['M', 'O']
5 | ['M']
6 | ['M', 'P']

SINGLETON-PROP-ON-VAR('5')
CONSTRAINT-FAILS: BinaryConstraint(5, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | Y*
3 | B*
4 | ['O']
5 | ['M']
6 | ['M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(5, 6) : Moose can't be next to Palin
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | B*
4 | ['O']
5 | ['M']
6 | ['M']

CONSTRAINT-FAILS: BinaryConstraint(5, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | Y*
3 | B*
4 | ['O']
5 | ['M']
6 | []

5. FAIL:
1 | Mc*
2 | Y*
3 | B*
4 | ['O']
5 | ['M']
6 | []

--------------------
6. EXAMINING:
1 | Mc*
2 | M*
3 | ['Y', 'M', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 3) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(3):
1 | Mc*
2 | M*
3 | ['Y', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'M', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | M*
3 | ['Y', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'M', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | ['Y', 'O', 'B']
4 | ['Y', 'M', 'O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(2, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | M*
3 | ['Y', 'O', 'B']
4 | ['Y', 'O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

6. CONTINUE:
1 | Mc*
2 | M*
3 | ['Y', 'O', 'B']
4 | ['Y', 'O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

--------------------
7. EXAMINING:
1 | Mc*
2 | M*
3 | Y*
4 | ['Y', 'O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | ['Y', 'O', 'B']
6 | ['P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | ['O', 'B']
6 | ['P']

SINGLETON-PROP-ON-VAR('6')
CONSTRAINT-FAILS: BinaryConstraint(6, 5) : McCain, Palin can't be next to Obama, Biden
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | ['B']
6 | ['P']

CONSTRAINT-FAILS: BinaryConstraint(6, 5) : McCain, Palin can't be next to Obama, Biden
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | []
6 | ['P']

7. FAIL:
1 | Mc*
2 | M*
3 | Y*
4 | ['O', 'B']
5 | []
6 | ['P']

--------------------
8. EXAMINING:
1 | Mc*
2 | M*
3 | O*
4 | ['Y', 'O', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | M*
3 | O*
4 | ['Y', 'B']
5 | ['Y', 'O', 'B']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : Obama, Biden must be next to each-other
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | O*
4 | ['Y', 'B']
5 | ['Y', 'O']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(3, 5) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(5):
1 | Mc*
2 | M*
3 | O*
4 | ['Y', 'B']
5 | ['Y']
6 | ['Y', 'P']

SINGLETON-PROP-ON-VAR('5')
CONSTRAINT-FAILS: BinaryConstraint(5, 4) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(4):
1 | Mc*
2 | M*
3 | O*
4 | ['B']
5 | ['Y']
6 | ['Y', 'P']

CONSTRAINT-FAILS: BinaryConstraint(5, 6) : No two seats can be occupied by the same person
DOMAIN-REDUCED-FOR-VARIABLE(6):
1 | Mc*
2 | M*
3 | O*
4 | ['B']
5 | ['Y']
6 | ['P']

SINGLETON-PROP-ON-VAR('4')
SINGLETON-PROP-ON-VAR('6')
8. CONTINUE:
1 | Mc*
2 | M*
3 | O*
4 | ['B']
5 | ['Y']
6 | ['P']

--------------------
9. EXAMINING:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | ['Y']
6 | ['P']

SINGLETON-PROP-ON-VAR('5')
SINGLETON-PROP-ON-VAR('6')
9. CONTINUE:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | ['Y']
6 | ['P']

--------------------
10. EXAMINING:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | Y*
6 | ['P']

SINGLETON-PROP-ON-VAR('6')
10. CONTINUE:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | Y*
6 | ['P']

--------------------
11. EXAMINING:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | Y*
6 | P*

11. SOLUTION:
1 | Mc*
2 | M*
3 | O*
4 | B*
5 | Y*
6 | P*

ANSWER: [('1', 'Mc'), ('2', 'M'), ('3', 'O'), ('4', 'B'), ('5', 'Y'), ('6', 'P')]
TREE:

ROOT
	1=Mc(c,1)
		2=Y(c,2)
			3=M(f,3)
			3=O(f,4)
			3=B(f,5)
		2=M(c,6)
			3=Y(f,7)
			3=O(c,8)
				4=B(c,9)
					5=Y(c,10)
						6=P(*,11)
			3=B(u,-)
		2=P(u,-)