Inverse

The inverse of a function is a function that undoes its effect, computing an argument that corresponds to the given result for that function. In APL it's usually written with the Power operator as. While some functions such as Reverse have an obvious exact inverse, others might have no valid inverse or many possible choices for a given result. Treatment of these cases varies among dialects, but a common rule is that the inverse should satisfy, making it a right inverse in mathematical terminology. A stand-alone inverse operator is defined in Kap, BQN ("Undo", ), and Uiua ("Un",  ).

As with Power in general, the dyadic inverse  is defined to be the inverse of , that is,.

Lessons

 * APL Cultivation 34

Documentation

 * Kap
 * BQN
 * Uiua
 * J Wiki