We don’t believe we invented the concept, surely someone else thought of it first.
The idea of Truth by definition is, if you create something, it is what you created, someone can’t say it’s wrong. Now it might not be useful, you might make mistakes when you use it, but it is what you made it.
We ran into this when we couldn’t find explanations for some things, and it occurred to us, maybe the authors don’t show a derivation because it was created, it simply is what they made it to be.
As an example, we don’t derive addition, we simply do it. Now we can point to how the idea develops when you start doing things like combining counts, and we could argue that addition comes from counting– we might have some fun on a project where we show things that help to give credibility to stuff that hasn’t been proved.