Equinumerosity
Two sets
A and
B are said to be
equinumerous if they have the same
cardinality, i.e., if there exists a
bijection f :
A -->
B. This is denoted
The study of cardinality is often called
equinumerosity. Sometimes the terms
equipollent or even
equivalent are used, though
equivalent is a bit overused. More at
cardinality.