逻辑函数的无冗余覆盖选择问题

逻辑函数的最小化算法可分为两大步骤：产生本源蕴涵项和在这些蕴涵项中选择一个最小覆盖。人说后者比前者更加困难，这的确是事实。我们这里提出一个无冗余和选择一个最小覆盖的算法。给定函数ｆ的一个本源覆盖Ｇ，首先将Ｇ分为三个子集：实质本源项子集Ｅ，完全冗余项子集Ｒ和相对冗余项子集Ｐ。然后在Ｐ中选择一个子集Ｐ＾＊，使Ｐ＾＊∪Ｅ为ｆ的一个近似最小覆盖。很明显，后一项任务比前者要复杂得多。所以，我们的讨论侧重于后

Derivation of Irredundant Cover for Logic Functions

Minimization algorithms of logic function involve two main steps: generation of prime impli-cants and extration of a minimal cover from those primes. It is said that the second step is more difficult than the first one, and it is true. We present a method for eliminating irredundant terms and selecting a near minimal cover with acceptable complexity. Given G, a prime cover of function /, first, we divide G into three subsets:essential primes E,complete redundances R and relative redundances P.Then we select a subset P* from P such that P' U E is a near minimal cover of f.Clearly, the later step is much more complex than the former. And this is why the discussion is emphased on it.