missing option "loose/strict" for searching by date

[wenamun]

copy&paste from the papyri.info/search website (see also online help for option "extended" on the EDH search for some more examples):

Loose date ranges encompass all documents which may have been in existence within their span; strict ranges only those documents whose dates fall within both ends of the range. For instance, suppose there exists a document dated between 150 - 350 AD. If a user selects a loose range of 100 - 200 AD, this document will be returned, as it may indeed have been in existence during that period. If the user switches to a strict range, however, this document will be excluded, as its latest possible date falls outside the bounds of the search.

default/only option in the moment in the EAGLE search is "loose", so there needs to be an option to choose "strict".

[PietroLiuzzo]

currently the query simply asks : http://search.eagle.research-infrastructures.eu/solr/EMF-index-cleaned/select?q=entitytype:artifact AND (notbefore:[15 TO 20] OR notafter:[15 TO 20])

which si loose and probably not a very clever query.

for a "strict" option (to be added to the requirements?) perhaps http://search.eagle.research-infrastructures.eu/solr/EMF-index-cleaned/select?q=entitytype:artifact AND (notbefore:[15 TO 20] AND notafter:[15 TO 20])

but this eventually in my understanding of this, which is poor, would simply force the presence of both information (which are not always given) and therefore looks like just an apparent restriction.

what happens in a strict search to something which is only dated notBefore 180 without a notAfter ?