PROLOG

• is interpreted.
• is declarative - contains a series of definitions which are accessed as required (in any order) by the program during execution.
• the HOW of solving the problem is NOT defined, only what is TRUE or NOT of a certain state of affairs is described.
• a statement can either be TRUE or FALSE
• a few built-in rules, and a few fundamental operations.

PASCAL programs contain a series of INSTRUCTIONS given to the computer as PROCEDURES to perform. The order of doing things is SPECIFIED and a number of ACTIONS performed as a consequence.

PROLOG programs contain a set of FACTS and RULES. Aspects of the problem which are TRUE or FALSE are described (defined), rather than the method to achieve a RESULT.

For instance :

	likes(omer, donuts) 
	likes(paul, neighbours)