anchor.diff:  match_anode(#anode{wme_constraint=Constr}, WME) when is_function(Constr, 1) ->
       Constr(WME).
   
  -match_token(#bnode{token_constraint=Constr,id=BNodeId}, Token) when is_function(Constr, 1) ->
  -    R=Constr(Token),
  -    ?ECHO({match_token, BNodeId, Token, R}),
  -    R.
  +match_token(#bnode{token_constraint=Constr,id=_BNodeId}, Token) when is_function(Constr, 1) ->
  +    Constr(Token).
   
       
   %%
  
positive.code:     end.
  
  join_right_bnode(#bnode{id=Id,right_key_fun=RightKeyFun}=BNode, {_Op,WME}=WMO, Env) ->
      ?ECHO(join_right_bnode),
      Key=RightKeyFun(WME),
      case modify_right_index(Id, Key, WMO, Env) of
          false -> % WM not modified
  
negative.code:     end.
  
  join_left_bnode(#bnode{id=Id,left_key_fun=LeftKeyFun}=BNode, _Op, Token, Env) ->
      Key=LeftKeyFun(Token),
      modify_left_index(Id, Key, _Op, Token, Env),
      FetchedWMEs=fetch_right_index(Id, Key, Env),
  