    # KEHOME/knowledge/applications/SemanticWeb/OpenCyc/Notes.Person.html
    # Sep/14/2003

# The bottom line: OpenCyc: Person isa* ?;

## Processing

The results were obtained using this MKR script.

    set echo=off,kbmode=cyc;
    #$Person iss* ?;

    set kbmode=mke,CommentMode=cyc;
    do check od knit done;

    do simplify lattice od #$Thing done;
    do check od knit done;

    #$Person iss* ?;
    exit;

MKE caching changes processing time from hours to minutes.

## Contradictions

OpenCyc states that a thing must be either an Individual or a Collection -- they are disjoint. But this context (#$UniversalVocabularyMt) does not enforce that distinction.

RDF has no contexts, and explicitly permits this same contradiction.

TAP permits this contradiction.

MKE enforces the unit/concept dichotomy as a matter of principle. The "same thing" cannot be both a unit and a concept in the same context.

## Combinatorial growth

OpenCyc has combinatorial growth in paths through the hierarchy. The "#$Person isa* ?;" lattice has 2840 different paths from #$Person to #$Thing. The simplified hierarchy has only 1172 different paths.

MKE uses disjoint, genus-differentia hierarchies/contexts. The "person isa* ?;" lattice has exactly 1 path from person to existent.

## Infinite loops

MKE consistency checks show 16 items in genls/specs loops.
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