Below is my CMU Ph.D. thesis submitted in 1993. Defines two versions of Tomabechi Algirithm which are fast full graph unification algorithms handling converging arcs and cyclic graph structures. The algorithm was used in Bechi Unit implementations in early and mid 90s which were one of the world's earliest implementations of digital currency.
Tomabechi algorithm was used for maintaining monotonicity in a coin data structure and virtual ledger data structures. I am receiving new requests for the thesis due to the surging interests in very efficient block chain like structures and maintenance of monotonic data structures using the algorithm.
Below is the link to the PDF scan of the thesis:
Full ANSI Common Lisp source code of Tomabechi Algorithm can be found at the end of the thesis.
http://maxpec.net/amazoncampaign_present/Dr_Tomabechi_treatise.pdf