Arity for InfectionFn

[apease]

We get the error

INFO in KB.checkArity(): Still performing Arity Check.....INFO in PredVarInst.hasCorrectArityRecurse(): Predicate InfectionFn does not have an arity defined in KB, can't get the arity number!
(InfectionFn ?M)

for InfectionFn in Medicine.kif. It should get arity 1 from its domain statement (domainSubclass InfectionFn 1 Microorganism) that should be picked up in KBcache.collectDomains(). The arity problem is triggered in PredVarInst.hasCorrectArityRecurse()