Quotes from the SIGGRAPH'96 Course No.11
Implicit Surfaces for Geometric Modeling and Computer Graphics
co-chaired by Jai Menon and Brian Wyvill
“Three major lines of work in implicit models:
“F-rep is an attempt to step to a more general modeling scheme using real functions.”
Download the first part of the SIGGRAPH'96 course No.11 (1.2 Mb PostScript zipped file) including
An Introduction to Implicit Techniques by J.Menon.