Plotkin, G. "Building-in Equational Theories." Machine Intelligence, vol. 7, 1972, pp. 73-90.
https://cir.nii.ac.jp/crid/1571698599605621504.
The paper Building-in Equational Theories by G. D. Plotkin describes the Pig-Pug algorithm for pattern matching in equational theories. This classic paper deserves a wider modern audience, but it appears to only be avalable in an inconvenient format. This repo provides the paper in a few different formats:
- PigPug.pdf, PDF format
- PigPug.tex, LaTeX source of the above
- PigPug.md, Markdown
- A scan of the original published paper is available at the (original source)