just use [==] ? that would do it. You can match the numbers to each other, or check whether either one equals the LCM, assuming you have a way to easily determine that…checking whether the numbers "reduce" with each other (technically, do they share any prime factors and if so, don’t count them twice) will take a bit of fiddling with [%] and [/]. If you don’t have that many psosible combinations, you can just hard-code the LCM’s manually by figuring them out beforehand.
If you want more than two numbers, try [match]
Sounds like some interesting polyrhyms are on the way…math and music? yes indeed…!