Injective Function

A function is injective (one-to-one) if different inputs map to different outputs, i.e. if and , then .

In other word, every element in the function’s codomain is the image of at most one element of its domain.

The term one-to-one function should not be confused with one-to-one correspondence, which refers to bijective function.

See also

• surjection
• bijective function