which, if compiled, might produce a lot of code ("print" statements being notorious) but further optimization is possible. This example makes reference only to "x(i)" and "x(i - 1)" in the loop (the latter only to develop the new value "x(i)") therefore, given that there is no later reference to the array "x" developed here, its usages could be replaced by a simple variable. Such a change would however mean a simple variable "whose value is changed" whereas if staying with the array, the compiler's analysis might note that the array's values are constant, each derived from a previous constant, and therefore carries forward the constant values so that the code becomes