%------------------------------------------------------------------------------
% File     : PHI001^0 : TPTP v9.0.0. Released v6.1.0.
% Domain   : Philosophy
% Axioms   : Axioms for Goedel's Ontological Proof of the Existence of God
% Version  : [Ben13] axioms.
% English  :

% Refs     : [Ben13] Benzmueller (2009), Email to Geoff Sutcliffe
% Source   : [Ben13]
% Names    :

% Status   : Satisfiable
% Syntax   : Number of formulae    :   12 (   3 unt;   4 typ;   3 def)
%            Number of atoms       :   49 (   3 equ;   0 cnn)
%            Maximal formula atoms :   10 (   4 avg)
%            Number of connectives :   61 (   0   ~;   0   |;   0   &;  61   @)
%                                         (   0 <=>;   0  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   15 (   5 avg;  61 nst)
%            Number of types       :    2 (   0 usr)
%            Number of type conns  :   29 (  29   >;   0   *;   0   +;   0  <<)
%            Number of symbols     :   15 (  14 usr;  10 con; 0-3 aty)
%            Number of variables   :   15 (  15   ^   0   !;   0   ?;  15   :)
% SPC      : TH0_SAT_EQU

% Comments : Requires LCL016^0.ax
%------------------------------------------------------------------------------
%----Signature
thf(positive_tp,type,
    positive: ( mu > $i > $o ) > $i > $o ).

thf(god_tp,type,
    god: mu > $i > $o ).

%----Constant symbol for essence: ess
thf(essence_tp,type,
    essence: ( mu > $i > $o ) > mu > $i > $o ).

%----Constant symbol for necessary existence: ne
thf(necessary_existence_tp,type,
    necessary_existence: mu > $i > $o ).

%----A1: Either the property or its negation are positive, but not both.
%----(Remark: only the left to right is needed for proving T1)
thf(axA1,axiom,
    ( mvalid
    @ ( mforall_indset
      @ ^ [Phi: mu > $i > $o] :
          ( mequiv
          @ ( positive
            @ ^ [X: mu] : ( mnot @ ( Phi @ X ) ) )
          @ ( mnot @ ( positive @ Phi ) ) ) ) ) ).

%----A2: A property necessarily implied by a positive property is positive.
thf(axA2,axiom,
    ( mvalid
    @ ( mforall_indset
      @ ^ [Phi: mu > $i > $o] :
          ( mforall_indset
          @ ^ [Psi: mu > $i > $o] :
              ( mimplies
              @ ( mand @ ( positive @ Phi )
                @ ( mbox
                  @ ( mforall_ind
                    @ ^ [X: mu] : ( mimplies @ ( Phi @ X ) @ ( Psi @ X ) ) ) ) )
              @ ( positive @ Psi ) ) ) ) ) ).

%----D1: A God-like being possesses all positive properties.
thf(defD1,definition,
    ( god
    = ( ^ [X: mu] :
          ( mforall_indset
          @ ^ [Phi: mu > $i > $o] : ( mimplies @ ( positive @ Phi ) @ ( Phi @ X ) ) ) ) ) ).

%----A3: The property of being God-like is positive.
thf(axA3,axiom,
    mvalid @ ( positive @ god ) ).

%----A4: Positive properties are necessary positive properties.
thf(axA4,axiom,
    ( mvalid
    @ ( mforall_indset
      @ ^ [Phi: mu > $i > $o] : ( mimplies @ ( positive @ Phi ) @ ( mbox @ ( positive @ Phi ) ) ) ) ) ).

%----D2: An essence of an individual is a property possessed by it and
%----necessarily implying any of its properties.
thf(defD2,definition,
    ( essence
    = ( ^ [Phi: mu > $i > $o,X: mu] :
          ( mand @ ( Phi @ X )
          @ ( mforall_indset
            @ ^ [Psi: mu > $i > $o] :
                ( mimplies @ ( Psi @ X )
                @ ( mbox
                  @ ( mforall_ind
                    @ ^ [Y: mu] : ( mimplies @ ( Phi @ Y ) @ ( Psi @ Y ) ) ) ) ) ) ) ) ) ).

%----D3: Necessary existence of an entity is the exemplification of all its 
%----essences.
thf(defD3,definition,
    ( necessary_existence
    = ( ^ [X: mu] :
          ( mforall_indset
          @ ^ [Phi: mu > $i > $o] :
              ( mimplies @ ( essence @ Phi @ X )
              @ ( mbox
                @ ( mexists_ind
                  @ ^ [Y: mu] : ( Phi @ Y ) ) ) ) ) ) ) ).

%----A5: Necessary existence is positive.
thf(axA5,axiom,
    mvalid @ ( positive @ necessary_existence ) ).

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