Euler Yet another proof Engine
Prolog Other
Latest commit 7e993bf Feb 27, 2017 @josd EYE main focus


                                  EYE readme

EYE is a reasoning engine supporting the RGB Semantic Web layers [1].
It performs semibackward reasoning and it supports Euler paths.

Semibackward reasoning is backward reasoning for EYE components i.e.
rules using <= in N3 and forward reasoning for rules using => in N3.

Euler paths are roughly "don't step in your own steps" and in that
respect there is a similarity with what Leonhard Euler discovered
in 1736 for the Königsberg Bridge Problem [2]. EYE sees the rule
P => C as P & NOT(C) => C.

Via N3 [3] EYE is interoperable with Cwm [4].

ETC [5] is used to test EYE releases [6].

EYE can be installed manually on Linux, Windows and MacOSX [7].
EYE is also available in a Docker container for command line use [8]
and in a Docker container for HTTP client use [9].

The main building blocks of EYE are depicted in [10].
The main focus is on EYE Unifying Logic plus EYE Reasoning.

The detailed design of EYE comprises:
 1/ N3 [3] parser specified as Prolog rules
 2/ N3Logic [11] to N3P (N3 P-code) compiler
 3/ EAM (Euler Abstract Machine) supporting Euler paths
 4/ proof construction using the vocabulary for proofs [12]
 5/ built-ins and support predicates for the above functionalities

This is what the basic EAM (Euler Abstract Machine) does in a nutshell:
 1/ Select rule P => C
 2/ Prove P & NOT(C) (backward chaining) and if it fails backtrack to 1/
 3/ If P & NOT(C) assert C (forward chaining) and remove brake
 4/ If C = answer(A) and tactic limited-answer stop, else backtrack to 2/
 5/ If brake or tactic linear-select stop, else start again at 1/

Design issues

Implicit Quantification in N3 [13]
  In ETC [5] implicit existentials in N3 formulae are standardized apart.

Proof output without bindings [14]
  In ETC [5] the variable substitutions naturally follow from the proof.

See also

EYE paper [15]
  Drawing Conclusions from Linked Data on the Web: The EYE Reasoner

EYE tutorial [16]
  Semantic Web Reasoning With EYE

EYE talk [17]
  EYE looking through N3 glasses

EYE logo [18]