Bag is the list of all instances of Template such 
that Tuple exists in the tuple-space. The behavior of 
variables in Tuple and Template is as in bagof/3. 
The variables could be existentially quantified with ^/2 
as in bagof/3. The operation is performed 
as an atomic operation. This predicate can fail due to a timeout. 
Example: Assume that only one client is connected to the server and that 
the tuple-space initially is empty.
  ?- out(x(a,3)), out(x(a,4)), out(x(b,3)), out(x(c,3)).
  true.
  ?- bagof_rd_noblock(C-N, x(C,N), L).
  L = [a-3,a-4,b-3,c-3] .
  true.
  ?- bagof_rd_noblock(C, N^x(C,N), L).
  L = [a,a,b,c] .
  true.