@prefix log: <http://www.w3.org/2000/10/swap/log.n3#> .
@prefix foaf:  <http://xmlns.com/foaf/0.1/#> .
@prefix ca: <coauthors.n3#> .

<>   log:forAll <#p> , <#h1> , <#h2> , <#a> , <#b> .

{ <#p> dc:author <#a>, <#b> .
  <#a> foaf:homepage <#h1> .
  <#b> foaf:homepage <#h2> . }
log:implies
{  <#a> ca:workedWithPersonOfHomepage <#h2> .
   <#b> ca:workedWithPersonOfHomepage <#h1> . } .