Addons - Include, Require?

Alright, say I make (Addon A), and then two other addons (Addon B and C) which both require the first ( Addon A) in order to run. I’d like ( Addon A) to run before (Addon B and C) do, as they both depend on ( Addon A).

If I add include(“filename”) to both addons that require the first addon, will that run the file from (Addon A) once or twice? does it check if the file was already run and not execute it a second time or does it simply run for every instance of include? In standard lua, I beleive ‘require’ exists for this purpose, but after what I can find on the gmod wiki, require is for modules specifically in gmod.