Instruction on programming in Logikus (or any other logic language) could easily fill a semester course. It is striking, then, that the grammar for the language contains just 20 rules. The grammar rules translate to fewer than 250 Java statements in LogikusParser.java . Language development lets you make a small amount of code go a long way.
The difficulty of learning Logikus derives not from a complex grammar but rather from the fact that Logikus addresses concepts orthogonal to Java. Java emphasizes modeling through objects, whereas Logikus emphasizes modeling through relations, facts, and rules.
Businesses have become increasingly aware that the one aspect of development that they cannot address with frameworks or off-the-shelf software is business logic. Thus, object-oriented development may become the province of framework developers, with application developers concentrating on developing business logic. Given this trend, it is well worth considering bringing rules to the surface of a system and employing a logic programming language such as Logikus.