The sum-of-squares isn't a continuation, rather it just loops through the squared-ints generator up to the bound.

call/cc is used to allow some form control and allow the loop to exit

> Before the sum-of-square function does anything, I use call/cc to capture the continuation, and assign it to the variable break. Notice that in the syntax of Scheme, this is the last step of the function. Therefore, calling break will immediately exist the function with a returned value, no matter where it is called.