1392	 Experience with FORMAC Algorithm Design	 Various facets of the design and implementation of mathematical expression manipulation algorithms are discussed. Concrete examples are provided by the FORMAC EXPAND and differentiation algorithms a basic FORMAC utility routine and an experiment in the extraction of the skeletal structure of an expression. One recurrent theme is the need to avoid excessive intermediate expression swell in order to minimize core storage requirements. Although many details from the FORMAC implementation are presented an attempt is made to stress principles and ideas of general relevance in the design of algorithms for manipulating mathematical expressions.
