Logic programming (which might better be called logical programming by analogy with mathematical programming and linear programming) is, in its broadest sense, the use of mathematical logic for computer programming. In this view of logic programming, which can be traced at least as far back as John McCarthy's [1958] advice-taker proposal, logic is used as a purely declarative representation language, and a theorem-prover or model-generator is used as the problem-solver. The problem-solving task is split between the programmer, who is responsible only for ensuring the truth of programs expressed in logical form, and the theorem-prover or model-generator, which is responsible for solving problems efficiently.
However, logic programming, in the narrower sense in which it is more commonly understood, is the use of logic as both a declarative and procedural representation language. It is based upon the fact that a backwards reasoning theorem-prover applied to declarative sentences in the form of implications:
If B1 and … and Bn then H
treats the implications as goal-reduction procedures:
to show/solve H, show/solve B1 and … and Bn.
For example, it treats the implication:
If you press the alarm signal button,
then you alert the driver of the train of a possible emergency
as the procedure:
To alert the driver of the train of a possible emergency,
press the alarm signal button.
The programmer is responsible, not only for ensuring the truth of programs, but also for ensuring their efficiency. In many cases, to achieve efficiency, the programmer needs to be aware of and to exploit the problem-solving behavior of the theorem-prover. In this respect, logic programming is like conventional imperative programming, using programs to control the behaviour of a program executor. However, unlike imperative programs, which have only a procedural interpretation, logic programs also have a declarative, logical interpretation, which helps to ensure their correctness. Moreover, such programs, being declarative, are at a higher conceptual level than purely imperative programs; and their program executors, being theorem-provers, operate at a higher conceptual level than conventional compilers and interpreters.
Reference:
http://en.wikipedia.org/wiki/Logic_programming
