The cryptarithm to solve:
a+b=c

Variables in this cryptarithm:
['a', 'b', 'c']

Variables that can't be zero:
['a', 'b', 'c']

Breadth-first Search:
{'a': 8, 'c': 9, 'b': 1}

The cryptarithm to solve:
i+bb=ill

Variables in this cryptarithm:
['b', 'i', 'l']

Variables that can't be zero:
['b', 'i']

Breadth-first Search:
{'i': 1, 'b': 9, 'l': 0}

The cryptarithm to solve:
ibm+hal=irix

Variables in this cryptarithm:
['a', 'b', 'h', 'i', 'l', 'm', 'r', 'x']

Variables that can't be zero:
['h', 'i']

Breadth-first Search:
{'a': 9, 'b': 2, 'i': 1, 'h': 8, 'm': 3, 'l': 4, 'r': 0, 'x': 7}

The cryptarithm to solve:
send+more=money

Variables in this cryptarithm:
['d', 'e', 'm', 'n', 'o', 'r', 's', 'y']

Variables that can't be zero:
['m', 's']

Breadth-first Search:
{'e': 5, 'd': 7, 'm': 1, 'o': 0, 'n': 6, 's': 9, 'r': 8, 'y': 2}