From the Axioms we have the Theorems, from which we derive the Rigorous Proof. In this case, the Proof of course is the Bible, which is why all material obtainable from there is placed under "Theorem" and not "Axiom".
Under this is a drawing of a tree. The Axioms are the roots, the Theorem is the main tree, and the Rigorous Proof consists of the branches. I have no idea how old this (unused) napkin is. Alas.