Is there a better alternative for "remainderless"?
Solution 1:
The notion of a remainder is associated with division -- it's what remains after subtracting the divisor as many times as possible. Note that the remainder is not the fraction part of the result. The remainder in 25/10 is 5, and the remainder in 20/8 is 4, even though those operations produce the same result.
There is no notion of a "remainder" associated with the logarithm.
I think you want to say that when b is a power of a, then your function produces an exact result.
Solution 2:
I guess what you're looking for is a variable or function called something like IsRemainderless, which would be true when there is no remainder. Well, that's certainly a mouthful. But isn't this the exact opposite of "HasRemainder"?
So, this is my proposal:
HasRemainder
It is up to you to self-document the program so that the reader and the maintainer understand how you've set this up.
If this is unacceptable for some reason, then you could go with
NoRemainder
which is a more succinct version of
HasNoRemainder