A Map Technique for Identifying Variables of Symmetry
L. M. Goodrich · Bell System Technical Journal · 1974
This paper presents a new map technique for identifying symmetrizable functions. The technique greatly reduces the work in ascertaining symmetricity, and it is unique in being also applicable to completely or incompletely specified functions which: (i) Contain imbedded symmetrizable function(s). (ii) Are the complement of a function of type (i). (iii) Contain an imbedded function of type (ii). Discussion of the technique and its extensions is included.