Goodness knows why my original comment is being downvoted. The formal term is 'primary program refinement' and can be found all over the place such as here: ht

Goodness knows why my original comment is being downvoted. The formal term is 'primary program refinement' and can be found all over the place such as here: http://p.web.umkc.edu/pgd5ab/cs_451/HW3/hw3.htm http://p.web.umkc.edu/pgd5ab/cs_451/HW3/hw3.htm