Timeline for What is a "general" relation algebra?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Jun 25 at 11:05 | answer | added | Adam Přenosil | timeline score: 2 | |
| Jun 25 at 9:59 | history | edited | YCor |
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| Jun 25 at 9:40 | answer | added | Tim Porter | timeline score: 2 | |
| Jun 25 at 9:36 | history | became hot network question | |||
| Jun 25 at 6:13 | comment | added | Tim Porter | I would expect the main question is 'what does 'right' mean in this context? Using the analogy with groups and then asking that somehow relation algebras should show the same behaviour seems a bit strange. Have you looked at the uses of relation algebras eg in the algebraic semantics of modal logics (cf article by Goldblatt, (2000) Algebraic Polymodal Logic: A Survey). There are lots of varieties of relational algebras which relate to well known relational structures and logics. I am not sure if that might go some way to answering your problem. | |
| Jun 25 at 3:59 | answer | added | Qiaochu Yuan | timeline score: 4 | |
| Jun 25 at 2:44 | comment | added | Joshua Grochow | Oh yeah, sorry, silly mistake on my part. I suppose one could ask if, e.g., RA is the variety containing RRA and with a finite equational axiomatization where that finite equational axiomatization is as short as possible (by some metric - number of axioms, numbers of characters, Kolmogorov complexity, ...), but that seems much harder to establish, if true. | |
| Jun 25 at 2:41 | comment | added | Qiaochu Yuan | @Joshua: can't you always make it smaller by adding any axiom in RRA that isn't in RA? | |
| Jun 25 at 2:38 | comment | added | Joshua Grochow | Is RA the smallest variety containing RRA and with a finite equational characterization? That wouldn't answer your question as stated, but, if true, could be taken as a different kind of evidence that these axioms are "the right ones". | |
| Jun 25 at 2:24 | answer | added | Keith Kearnes | timeline score: 7 | |
| Jun 25 at 1:34 | history | asked | Noah Schweber | CC BY-SA 4.0 |