incorrect result with aggregate "MIN"

[pchampin]

According to the spec, the MIN aggregation function "makes use of the SPARQL ORDER BY ordering definition".

By that definition, IRIs come before literals, and CORESE complies with that for ORDER BY. However, it does not for MIN.

Example:

SELECT (MIN(?x) as ?a) { VALUES ?x { 3 <x:1> 4 <x:2> } }

retuns 3 instead of <x:1>.