I'm working on creating graphs of derivations in physics and am searching for prior work in this area. As an example, I've posted pictures of the graph of Euler's equation https://physics-equations-graph.googlecode.com/svn/trunk/euler_equation_trig_sqrd_no_labels.png and for the simple harmonic oscillator https://physics-equations-graph.googlecode.com/svn/trunk/simple_harmonic_oscillator_no_labels.png (right click on link and save as to download picture -- direct link doesn't seem to work.) The idea is that a derivation is composed of equations and descriptions of how the equations are related. I'm calling the equations "statements" (red ovals in the pictures) and the relations between statements "grammatical rules" (red trapezoids in the pictures). I expect there are a finite number of these grammatical rules. One of the goals of my project is to enumerate these grammatical rules. The problem I would like to resolve is how this project relates to prior work. I'm not sure what has already been done by others, which is why I started from scratch and am inventing jargon. There seems to be an overlap with physics, math, and possibly linguistics. However, I've found no references in any of these areas. Somewhat related is the work being done with OpenMath but this only applies at the "statement" level. Computer algebra systems can be used to verify individual "grammatical rules," but that is the limit of their usefulness. Please let me know if you have suggestions for related work. Thanks in advance.