Tips:

• "Loose" propagations can be done by making dummy variables in the form of cell references (A1, A2, etc.)
• Sheet specified references will be treated separate from implicit.
• This system is only good at "math" functions (e.g. tan(), ln(), sqrt()) right now. (no xlookup() or average())

Sources:

• Using my fork of Deriv.
• Huge thanks to Hugh O'Reilly's original repo!
• MathJax to render LaTeX.

TODO:

• Add overall err prop equation sqrt(sum()) with step-by-step evaluation from the placeholder variables
• Add hover events to td elements for clipboard interactions
• Figure out LaTeX to image to clipboard pathway
• Add loading popups to give feedback
• Combine all variable settings into one table at top of output
• Incorporate error cell setting for each variable.
• Fix decimal passing in deriv.
• Allow mixing of "$A$5" with "$A5" or "A5" (separate group for sheet-specified).
• Allow mixing of "$A$5" with "Sheet4!$A$5" (add check for match neighbors).
• Add understanding of propagation for basic functions like AVERAGE(), STDEV(), and LINEST().