Talk:Nominal terms (computer science)

Topic
Shouldn't this article be about nominal logic instead? We lack one for the more general topic, don't we? I take it nominal unification (the ref just added) is unification in nominal logic... Pcap ping  20:38, 13 May 2010 (UTC)

Actually, this logic appears to be only equational (p. 6 in Urban and Pitts). FYI, Wikipedia lack even an article on the 1930's vintage equational logic, never mind the recent (naming aware) developments. Pcap ping  20:46, 13 May 2010 (UTC)

No, nominal logic is a theory inside first-order logic which allows you to do "nominal style reasoning". Nominal terms are something altogether. The two are closely related though, as they both came out of the same research programme, and both have a history/foundation in nominal sets. An article on nominal logic should be added to Wikipedia, though.

When you say the logic appears to be equational, to what are you referring? Nominal terms *aren't* an equational logic, they're just a syntax. There are two equational logics that use the syntax though: nominal algebra, and nominal equational logic. What you are probably looking at are the derivable alpha-equivalence rules for nominal terms. Consequently, nominal unification is unification between nominal terms (the relevant unification algorithm for nominal logic is first-order unification).

We do have a Wiki article on a more general topic: Nominal techniques, though I have reduced this to a stub. I plan to add more about nominal sets there. DPMulligan (talk) 21:16, 13 May 2010 (UTC)