As you know, Sandro had posted some of your comments as public comments to the RIF public comment list, which require a response. Apologies for taking so long, we were more focused on technical details.
> I'm a little puzzled to see no reference to KIF, > especially given the existence of > http://www.w3.org/2000/07/hs78/KIF.html
Yes, thanks for pointing this out. A reference to KIF, Common Logic, and Conceptual Graphs was added to the BLD Overview section. Of course, BLD has many influences, and not all are specifically mentioned.
> The "mapping between RIF-BLD and KIF" information doesn't have to be > in the RIF-BLD specification, but it should *exist* and the RIF-BLD > specification should point to it and explain briefly why KIF won't do.
We never planned to have any formal relationship (ie mapping) with KIF, but with Common Logic. KIF has no status as far as I'm aware, other than being the basis of at least eight different implementations whose syntactic and semantic divergence was the very inspiration for starting the CL effort.
> The "mapping between RIF-BLD and SPARQL" information doesn't have > to be in the RIF-BLD specification, but it should *exist* and the > RIF-BLD specification should point to it and explain briefly why > SPARQL won't do.
Yes, we expect someone will write something like this, but it hasn't been done yet. We added a paragraph in the overview discussing SPARQL.
> I think an ISO standard for logic interchange *has* to > be cited by the RIF specifications. Especially given > its requirement > "5.1.3 Common Logic should be easy and natural for use on the Web".
We added citations to CL to the BLD overview, with a short discussion of the differences. However, there is no mapping to CL, and this was simply an issue of working group resources. RIF started as a very large working group, that included several active members of the CL community, however in the intervening 3 years all the CL members became inactive (except me, and I don't have time to do it). As with Sparql, I think it will happen and we will rely on the external community to provide it, but we lacked resources (people and time) in the group to do it. It shouldn't be hard, by all accounts BLD is quite a simple first-order language, but the "devil is in the details".