NOUN: <plural> == <case of "<origin>"> <case of latin masculine> == -i <case of latin neuter> == -a <case of> == -s <origin> == norman. Cat: <> == NOUN. Datum: <> == NOUN <origin> == latin neuter. Alumnus: <> == NOUN <origin> == latin masculine.Here the value of the <origin> attribute of a noun (denoting its etymological source) is used to determine the value of its <plural> suffix. Thus we can derive the following extensional statements:
Cat: <plural> = -s. Datum: <plural> = -a. Alumnus: <plural> = -i.
We do not need to invoke an attribute called case to get this technique to work. For example, in Section 2, we gave the following definition of <mor form> in terms of <syn form>:
VERB: <mor form> == <mor "<syn form>">.Here the feature <syn form> returns a value (such as passive participle or present tense sing three) which becomes part of the path through which <mor form> inherits. This means that nodes for surface word forms need only state their parent lexeme and <syn form> feature in order for their <mor form> to be fully described. So, as we saw in Section 2 above, the passive participle form of sew is fully described by the node definition for Word3.
Word3: <> == Sew <syn form> == passive participle.For finite forms, we could use a similar technique. From this,
Word4: <> == Sew <syn form> == present sing third.we would want to be able to infer this:
Word4: <mor form> = sew sHowever, the components of <syn form>, present, sing, third are themselves values of features we probably want to represent independently. One way to achieve this is to define a value for <syn form> which is itself parameterised from the values of these other features. And the appropriate place to do this is in the VERB node, thus:
VERB: <syn form> == "<syn tense>" "<syn number>" "<syn person>".This says that the default value for the syntactic form of a verb is a finite form, but exactly which finite form depends on the settings of three other paths, <syn tense>, <syn number> and <syn person>. So now we can express Word4 as:
Word4: <> == Sew <syn tense> == present <syn number> == sing <syn person> == third.This approach has the advantage that the attribute ordering used in the <mor...> paths is handled internally: the leaf nodes need not know or care about it. Thus Word3 remains unchanged, overriding the definition of <syn form> and so not requiring these additional features to be defined at all, nor making any use of them if they are defined.