I was curious too. Here are two papers I found, but they are both paywalled: Introduction to FORMAC (Sammet and Bond, 1964): http://ieeexplore.ieee.org/documen

I was curious too. Here are two papers I found, but they are both paywalled: Introduction to FORMAC (Sammet and Bond, 1964): http://ieeexplore.ieee.org/document/4038202/ http://ieeexplore.ieee.org/document/4038202/ The beginning and development of FORMAC (Sammet, 1993): https://dl.acm.org/citation.cfm?doid=154766.155372 https://dl.acm.org/citation.cfm?doid=154766.155372 From what I gathered reading a few snippets of other sources, FORMAC was one of the first systems to do symbolic math, like an early Mathematica.