eye2-swipl

• A reasoner using webized prolog which basically means that atoms can be IRIs.
• Besides top-down reasoning with conclusion :- premise rules, it also does bottom-up reasoning with conclusion ?- premise rules.
• Bottum-up reasoning can use stable(n) to fail if the deductive closure at level n is not yet stable.
• Proofs steps are explains((conclusion ?- premise), premise_inst, conclusion_inst) and conclusion_inst is asserted.
• Variables are interpreted as universally quantified variables except for conclusion ?- premise conclusion-only variables which are interpreted existentially.
• Queries are posed as true ?- premise and answered as answer(premise_inst).
• Inference fuses are defined as false ?- premise and blown as fuse(premise_inst) with return code 2.

Rationale for bottom-up reasoning with conclusion ?- premise rules

• conclusion can be a conjunction
• conclusion can be false to blow an inference fuse
• conclusion can be true to pose a query
• conclusion can not be any other built-in
• conclusion-only variables are existentials
• current way to explain the reasoning as explains proof steps
• avoiding loops that could occur with backward chaining

Installation and test

Install SWI-Prolog and run

cd etc
./test

Background

• Personal notes by Tim Berners-Lee: Design Issues
• Book of Markus Triska: The Power of Prolog