Today's Word of the Day means...
inverse Adjective (ĭnvûrs') Relating to a mathematical operation whose nature or effect is the opposite of another operation. For example, addition and subtraction are inverse operations, as are multiplication and division. Noun (ĭn'vûrs')

mathematics
Given a function, f : D > C, a function g : C > D is called a left inverse for f if for all d in D, g (f d) = d and a right inverse if, for all c in C, f (g c) = c and an inverse if both conditions hold. Only an injection has a left inverse, only a surjection has a right inverse and only a bijection has inverses. The inverse of f is often written as f with a 1 superscript.
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