Class of Algorithms where finding output of algorithm can be aided by output of same algorithm given a similar input
It can be algorithms which use initial guess, for example algorithms for finding roots and local minimums/maximum like Newton's method and gradient descend. Here g and x are functions, and g is close to x means that they have roots or local minimums/maximums in similar locations, so taking A(g) as initial guess, algorithm can converge faster to A(x).