Formal Concept Analysis is an emergent area in the topic of data analysis based on lattice theory. In this framework, a context is defined as the relation between a set of objects and a set of attributes and from here it is possible to extract relevant knowledge. One of the important topics is to study the implications between the attributes considered. In a context, some equivalent sets of implications can be compute using different techniques. We are studying the direct optimal basis, which enables us to compute the closure of a set of attributes in just one iteration. A Prolog method has been implemented that computes a direct basis from a set of implications.