Abstract
Both the conventional Karnaugh map (CKM) and the variable-entered Karnaugh map (VEKM) are powerful manual tools that have many pictorial and pedagogical advantages. However, while the CKM is suitable only for small-sized problems, the VEKM can handle more variables and hence can be used for a variety of mediumsized applications. This paper presents an advanced and further improved VEKM procedure that aims at obtaining most, if not all, of the irredundant disjunctive forms of an incompletely-specified switching function (ISSF). This procedure differs from previous ones in two respects. First, it is a rather elaborate one employing the concept of the generalized consensus of a set of terms. Second, it uses a more systematic and more precise two-pass strategy that is more likely to capture minor details in the intrinsic structure of the ISSF under consideration. This procedure is intended as a supplement rather than a replacement of more powerful algorithms that have computer implementations but are too complicated to have some graphical insight for the user. Two detailed examples are given to illustrate the rules and steps of the new procedure and to demonstrate its efficiency and power.