%--------------------------------------------------------------------------
% File     : LCL004-2 : TPTP v7.2.0. Released v2.3.0.
% Domain   : Logic Calculi (Propositional)
% Axioms   : Propositional logic deduction axioms for EQUIVALENT
% Version  : [WR27] axioms.
% English  :

% Refs     : [WR27]  Whitehead & Russell (1927), Principia Mathematica
% Source   : [WR27]
% Names    :

% Status   : Satisfiable
% Syntax   : Number of clauses    :    1 (   0 non-Horn;   1 unit;   0 RR)
%            Number of atoms      :    1 (   1 equality)
%            Maximal clause size  :    1 (   1 average)
%            Number of predicates :    1 (   0 propositional; 2-2 arity)
%            Number of functors   :    3 (   0 constant; 2-2 arity)
%            Number of variables  :    2 (   0 singleton)
%            Maximal term depth   :    3 (   2 average)
% SPC      : 

% Comments : Requires LCL004-0.ax LCL004-1.ax
%--------------------------------------------------------------------------
cnf(equivalent_defn,axiom,
    ( equivalent(P,Q) = and(implies(P,Q),implies(Q,P)) )).

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