Consider the pseudo-procedure below:

--beg
    if (condition_a)
        condition_b = true;
    while (condition_a and condition_b)
        •••Do something that can mutate condition_a and/or condition_b•••
--end

_{condition_b is an already existing condition that must be set to true (if condition_a is true) before the loop will even start.}

condition_a is tested twice which is “unnecessary”. I want to remove the “unnecessary” test. ^[1][2]

I considered the following:

• repeat-until.
• Set condition_b at the start of each loop iteration.

All will lead to multiple setting of condition_b which is also an O(n) test of the condition (worse than my original intention).

What other approach will you suggest?

_{^[1] The use of “unnecessary” is completely subjective and it is actually the premise of this question. I feel like the first test can be avoided and the second test, which is the most significant one, should suffice.}

_{^[2] If you disagree with it being unnecessary, please prove your claim of its necessity.}