The core objective of the Physics Derivation Graph is identifying the mathematical connectivity of the various domains of Physics. The same connectivity should be able to relate "basic" Physics (e.g., F=ma) to advanced Physics (e.g., the theory of the Standard model, string theory).
I know of two ways to document the connectivity:
identify symbol re-use
identify inter-related derivations at the level of expressions
The symbol re-use is less interesting than the re-use of expressions.
but I didn't specify what would qualify as sufficient to show completeness.
What core expressions are representative of all of Physics? Are there a set of expressions that, if shown to be connected by derivations, would be sufficient to demonstrate the span of the concept?
I expect that, for any given subdomain of Physics, there are central expressions. The task list is then