An entry names the alternative, says what the KB states instead, and gives the reason.
Alternative: intangible means "has no mass", and everything without mass is one kind.
Instead: thing is partitioned three ways, each on its own axis: (partition thing tangible intangible) by mass, (partition thing spatial aspatial) by location in space, and (partition thing temporal atemporal) by location in time. nowhere_never names what is aspatial and atemporal.
Why: mass and location come apart. A region of space has a location and no mass. A line such as y=x is placed in a space and has no mass. A number has neither. With one axis, "massless" sweeps a region together with a number, and every rule about located things has to exclude the massless ones by hand. With three axes, each rule names the axis it is about, and the disjointness audit reads the pairs between axes as overlapping.
Alternative: (genl event spatiotemporal): every event happens somewhere and somewhen.
Instead: event is temporal, through (genl situation temporal) in CxCore, and the KB states no place for an event as such.
Why: some events have a time and no place. A contract expiring, a debt falling due and a term of office ending each happen at a time and nowhere in particular, and each can cause things. Requiring a place would either exclude them from event or force an invented location.
orthogonal for axes that cut across each otherAlternative: relate cross-cutting types with disjoint or separating, or leave their relationship unstated.
Instead: (orthogonal A B) states that A and B overlap and neither subsumes the other, for example made and biological.
Why: the types on different axes are neither disjoint nor nested. A bred animal is made and biological. Left unstated, every such pair reads :unknown in the disjointness audit, which hides the pairs that are open questions among hundreds that are settled. Stating them disjoint would be false. orthogonal records the settled overlap, so the audit's unknowns are the real open questions.
transitiveInArg points the way Cyc's doesAlternative: give transitiveInArg and transitiveInArgInverse the directions opposite to Cyc's transitiveViaArg and transitiveViaArgInverse.
Instead: each name carries the direction of the Cyc predicate it matches, and a test pins the direction each carries along genl.
Why: readers arrive from Cyc's documentation. A predicate whose name matches Cyc's and whose direction is opposite gets used backwards, and the result is a KB that derives the wrong memberships with no error. Apart from Cyc, this direction is also the one most readers expect the name to mean.
capability typeAlternative: a capability type whose instances are abilities (flying, swimming), related to their holders by hasCapability.
Instead: no capability type. The second argument of hasCapability and capabilityType is an event kind: flying and travelling are kinds of event.
Why: an ability is an ability to take part in a kind of event, and the event vocabulary already carries the structure abilities need. (genl flying travelling) makes "can fly implies can travel" fall out of the event hierarchy with no parallel ability hierarchy to keep in step, and travelling being a causal_event is stated once, for the events and the abilities together.
Alternative: keep alive, dead, mortal, asleep, awake, breathes_air and warm_blooded free of genls, on the rule that a property is not a type.
Instead: each property takes the genl it is true of: alive and dead under biological, and the other five under organism or animal.
Why: only a living kind of thing can be alive, asleep or warm-blooded. Without a genl, nothing stops (warm_blooded Rock1), and every pair of these properties with the kinds below organism reads :unknown in the audit. With the genl, a misapplied property is caught as a type clash. alive and dead go under biological rather than organism, so a dead leaf is not concluded to be an organism.
Alternative: state that every metal is solid, or leave metal's state of matter unstated.
Instead: in CxNormalPhysicalConditions, the states of matter at room temperature, metal is a solid by default, and mercury is the stated exception.
Why: a monotonic "every metal is solid" is false, because mercury is liquid at room temperature. Leaving the state unstated gives up a conclusion that is right for almost every metal anyone will mention. A default states the common case, and the exception keeps the one known counterexample from contradicting it. The choice between a default and a list of the known solid metals turns on new cases: a newly discovered metal, a hypothesized one, or one in a fictional or counterfactual context should come out solid unless something says otherwise. A list would conclude nothing about any of them, so the default is the right form (default or enumerate in the principles).
empty and nonempty partition unary_predicateAlternative: leave it implicit that a type below two disjoint types has no members.
Instead: (partition unary_predicate empty nonempty), carried down and up genl. A type below two disjoint types is concluded empty, and the disjointness audit does not treat a shared subtype as evidence of overlap unless the subtype is known to be nonempty.
Why: (disjoint c c) holds exactly when c is empty, so an empty type is disjoint from everything, itself included. Left implicit, an empty shared subtype would be counted as an overlap witness and the audit would report two disjoint types as overlapping. Naming emptiness makes that case explicit, so the audit can ask for a witness that something is actually there.
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