Thank you for the report. However, there's no bug here and I'm going to reject this ticket.
> Another option is to make it return 5 (kinda DWIM) No, it's not another option because that doesn't make any sense mathematically. The math operations lcm[^1] and gcd[^2] ops perform apply to integer operations. The ops are speculated, implemented, and clearly documented to be operations coercing to integral types to match that. As there's no calculation result that can be expected from non-integral types, throwing on non-Ints will only force the user to add Int coercers to their code all the time, which is quite annoying. [1] https://en.wikipedia.org/wiki/Least_common_multiple [2] https://en.wikipedia.org/wiki/Greatest_common_divisor
