%------------------------------------------------------------------------------
% File     : LCL523+1 : TPTP v8.2.0. Released v3.3.0.
% Domain   : Logic Calculi (Propositional modal)
% Problem  : Prove axiom 4 from KM5 axiomatization of S5
% Version  : [HC96] axioms.
% English  :

% Refs     : [HC96]  Hughes & Cresswell (1996), A New Introduction to Modal
%          : [Hal]   Halleck (URL), John Halleck's Logic Systems
% Source   : [TPTP]
% Names    :

% Status   : Theorem
% Rating   : 0.56 v8.2.0, 0.58 v8.1.0, 0.56 v7.5.0, 0.59 v7.4.0, 0.57 v7.3.0, 0.69 v7.2.0, 0.72 v7.1.0, 0.70 v7.0.0, 0.67 v6.4.0, 0.69 v6.3.0, 0.67 v6.2.0, 0.76 v6.1.0, 0.80 v6.0.0, 0.78 v5.4.0, 0.82 v5.3.0, 0.85 v5.2.0, 0.75 v5.1.0, 0.76 v5.0.0, 0.75 v4.1.0, 0.78 v4.0.0, 0.75 v3.7.0, 0.80 v3.5.0, 0.74 v3.4.0, 0.79 v3.3.0
% Syntax   : Number of formulae    :   82 (  24 unt;   0 def)
%            Number of atoms       :  149 (  11 equ)
%            Maximal formula atoms :    4 (   1 avg)
%            Number of connectives :   67 (   0   ~;   0   |;   3   &)
%                                         (  49 <=>;  15  =>;   0  <=;   0 <~>)
%            Maximal formula depth :    6 (   3 avg)
%            Maximal term depth    :    5 (   2 avg)
%            Number of predicates  :   60 (  59 usr;  58 prp; 0-2 aty)
%            Number of functors    :    9 (   9 usr;   0 con; 1-2 aty)
%            Number of variables   :  110 ( 110   !;   0   ?)
% SPC      : FOF_THM_RFO_SEQ

% Comments :
%------------------------------------------------------------------------------
%----Include Hilbert's axiomatization of propositional logic
include('Axioms/LCL006+0.ax').
include('Axioms/LCL006+1.ax').
include('Axioms/LCL006+2.ax').
%----Include axioms of modal logic
include('Axioms/LCL007+0.ax').
include('Axioms/LCL007+1.ax').
%----Include axioms for KM5
include('Axioms/LCL007+2.ax').
%------------------------------------------------------------------------------
fof(km4b_axiom_4,conjecture,
    axiom_4 ).

%------------------------------------------------------------------------------