@prefix e: <http://eulersharp.sourceforge.net/2003/03swap/log-rules#>.
@prefix list: <http://www.w3.org/2000/10/swap/list#>.
@prefix log: <http://www.w3.org/2000/10/swap/log#>.
@prefix kb: <http://deductions.sf.net/ontology/knowledge_base.owl#> .
@prefix string: <http://www.w3.org/2000/10/swap/string#>.
@prefix tln: <http://www.nie.org/ontology/nietzsche#>.

# merge images if they share a common filename and have two different pages on them.

{  
   ?manuscript a tln:ArchivalManuscriptUnity;
      tln:hasPages ?pages.
   ?page_a list:in ?pages;
      tln:hasImage ?image_a.
   ?page_b list:in ?pages;
      tln:hasImage ?image_b.
   (?before (?page_a) ?middle (?page_b) ?after) list:append ?pages. # asymmetric condition: page_a before page_b
                                                                    # we keep image_a and get rid of image_b.
   ?image_a tln:hasFileName ?file_name;
      tln:hasTextField ?text_field_a.
   ?image_b tln:hasFileName ?file_name;
      tln:hasTextField ?text_field_b.
   ?image_a log:notEqualTo ?image_b.
   ?image_b ?p ?o.
   ?page_b ?has ?image_b.
} => { 
   ?image_a ?p ?o.
   ?page_b ?has ?image_a.
   _:d kb:retract (?image_b ?p ?o).
   _:d kb:retract (?page_b ?has ?image_b).
}.