Anony's response was pointing out that all of this is standard Computer Science 101: every deterministic loop has three logical parts, but any processor really just needs "if" and "jump."

Early FORTRAN used very low-level syntax. Every conditional was an IF/GOTO. This was mostly because nobody was trying to make better compilers yet. C highlighted the three logical parts with for(;;) to show that it's a high-level language. Sort of the opposite of what you might expect, from today's sensibilities.

Perl may offer high-level syntax, but it's all really just iffing and jumping (renamed to "and" and "goto") under the sheets.