Define a higher-order function forloop that takes three arguments: an initial value (counter) representing the initial value of the loop counter, a function (condition) representing a test expression with a single argument, and a function (increment) representing the loop counter increment function with a single argument. It outputs another function that, when run with a function as argument (say, loopbody), runs loopbody starting with the initial value of the loop counter until the condition returns false, while incrementing the loop counter using the increment function.

The examples here assume the following function definitions:

Some examples of using the forloop function are presented here: