parid0446 | 28 Jan 2003 16:49:30
The Conformance clause needs to be more specific about the constraints that the RM places on implementations, even if the information in the Conformance clause is redundant. Here are some ideas about how to be more specific about what it means for software to be RM-conformant. (1) RM conformant software accurately implements an RM-conformant model. (2) Since RM-conformant models can impose many strange and wonderful constraints on their software implementations, we can't say, comprehensively, how RM-conformant software behaves. A lot of the behaviors will necessarily be model-defined. (3) However, we can state certain minimum global constraints on all implementations, in general terms. Here are some proposals: (a) If a subject can implicitly exist, but can't be a role player, according to the model in terms of which a topic map is exported by an implementation, that subject must not have any proxies (
Software conforms to the RM if it implements an RM-conformant model in a way that conforms to that model, and, additionally, if its implementation of syntactical representations of that model conform to the specifications of those syntaxes.
The constraints placed on models were harder to work out, but the summary seems to be that it must be possible to impose an RM-consistent view on the models, which seems to me like a good way to formulate this. It means the models can be specified according to many different world-views and still be judged using the RM. The constraints on seem to be as follows (I'm assuming the first of the two interpretations given in the table above): - proxies for subjects must either - support being role players, (and if so, - be capable of participating in any assertions not restricted by the model (3b), - have a well-defined equality rule (3c) - not support being role players, in which case I can't see any constraints on them. (Did I miss something?) In addition come the constraints in 3f, which I must confess I don't fully understand. They seem reasonable, but more explanation of them would be welcome.
One thing worthy of note is that it seems to me that these constraints are somewhat tautological if the mapping from the models to be tested for conformance to the RM are left unspecified. In that case it seems to me that for *any* model whatsoever it will be possible to create a mapping that produces a conforming model.
As far as I can see there are also constraints on the syntactical expressions of RM-conforming models; that is, constraints on the specifications of the syntaxes of RM-conforming models. This is, as far as I understand: - subjects whose proxies cannot be role players are not allowed to have syntactical proxies (3a).