
set(breadth_first).
assign(max_weight, 48).

formulas(assumptions).

% The problem is to prove reflexivity from the
% equivalential calculus (EC) single axiom XCB.

% Prover9 should produce a proof in a few seconds.

  -P(e(x,y)) | -P(x) | P(y) # label(condensed_detachment).

  P(e(x,e(e(e(x,y),e(z,y)),z))) # label(XCB).

end_of_list.
  
formulas(goals).

  P(e(x,x)) # label(Reflexivity).

end_of_list.

  
