This paper presents a cubic graph by which it is unnecessary to decompose each
monomial into miniterms for minimizing multivariate switching functions of single-output.
The method for obtaining "non-redundant" cover and the method which is called "orded
array method" for finding "minimal" cover are also presented; The minimization of
switching functions with more than six variables that cannot be solved by Karnaugh graph, may
be solved by these methods. Souch methods can be applied to the simplification of logic
circuits, digital control etc. The algorithms presented in this paper has been implemented
on the computer C'J-719.