COSMAS:
 - disjunctions with more than 2 arguments are parsed hiearchically by ANTLR grammar:
   "A oder B oder C" becomes (simplified) "A|(B|C)" 
 - distance operators are a little hard to process, using a stack of "distantTokenGroups" containing empty tokens to keep track of
   the operators, insert the tokenGroups on top of this stack before second argument
 - using stacks proves to be a good choice for tree processing