- From: Lee Feigenbaum <lee@thefigtrees.net>
- Date: Thu, 25 Oct 2007 11:02:54 -0400
- To: Olaf Hartig <hartig@informatik.hu-berlin.de>
- CC: public-rdf-dawg-comments@w3.org
Olaf Hartig wrote: > Hello, > > I'm a bit puzzled what exactly the result of the algebra operators defined in > section 12.4 is. Is it a set of solution mappings or a multiset? > I guess it is a multiset, as suggested by the equations with the cardinalities > in the definitions. Additionally, it makes more sense to me (esp. w.r.t. > nesting of algebra operators). However, the definitions use braces which > suggest sets, because braces are usually used to denote sets. Hi Olaf, The result of each operator is a multiset, specified by a set of solutions and a mapping from each solution in the set to a cardinality value. Each operator's definition gives the set results of the operation (in curly braces) and the cardinality of each element of the set. Lee
Received on Thursday, 25 October 2007 15:03:05 UTC