Standard minimum transition time secondary assignments for asynchronous circuits

Two general types of standard minimum transition time secondary assignments for arbitrary r-row flow tables are derived. One class requires 1/2 no(no + 1) secondary variables, no = [log2 r], and the second, a comparable number but less than 1/2 no(no + 1). These standard assignments thus provide a significantly better lower bound for any flow table than other standard assignments which require 2no-1 secondary variables. The derivation of the assignments is based upon adding auxiliary u-variables to a basic set of no y-variables; the u-variables are modulo two sums over various subsets of the y-variables.