Loops are theoretically interesting and rich and with the right tools even the most complex cases can be written clearly and reasoned about easily. https://www.

Loops are theoretically interesting and rich and with the right tools even the most complex cases can be written clearly and reasoned about easily. https://www.cs.utexas.edu/users/EWD/transcriptions/EWD03xx/EWD316.4.html https://www.cs.utexas.edu/users/EWD/transcriptions/EWD03xx/E... is a good example of how mathematical reasoning is just as applicable to "imperative" programming as it is to "functional." https://en.wikipedia.org/wiki/Hoare_logic https://en.wikipedia.org/wiki/Hoare_logic describes the syntax used.