% Mizar problem: t20_pboole,pboole,501,52 
fof(t20_pboole,conjecture,(
    ! [A,B] : 
      ( m1_pboole(B,A)
     => ! [C] : 
          ( m1_pboole(C,A)
         => ! [D] : 
              ( m1_pboole(D,A)
             => ( r2_pboole(A,B,C)
               => ( r2_pboole(A,k2_pboole(A,B,D),k2_pboole(A,C,D))
                  & r2_pboole(A,k2_pboole(A,D,B),k2_pboole(A,D,C)) ) ) ) ) ) ),
    inference(mizar_bg_added,[status(thm)],[commutativity_k2_pboole,dt_k2_pboole,dt_m1_pboole,existence_m1_pboole,idempotence_k2_pboole,rc1_funct_1,reflexivity_r2_pboole,t15_pboole,t16_pboole,t18_pboole]),
    [file(pboole,t20_pboole)]).

fof(commutativity_k2_pboole,axiom,(
    ! [A,B,C] : 
      ( ( m1_pboole(B,A)
        & m1_pboole(C,A) )
     => k2_pboole(A,B,C) = k2_pboole(A,C,B) ) ),
    file(pboole,k2_pboole),
    []).

fof(dt_k2_pboole,axiom,(
    ! [A,B,C] : 
      ( ( m1_pboole(B,A)
        & m1_pboole(C,A) )
     => m1_pboole(k2_pboole(A,B,C),A) ) ),
    file(pboole,k2_pboole),
    []).

fof(dt_m1_pboole,axiom,(
    ! [A,B] : 
      ( m1_pboole(B,A)
     => ( v1_relat_1(B)
        & v1_funct_1(B) ) ) ),
    file(pboole,m1_pboole),
    []).

fof(existence_m1_pboole,axiom,(
    ! [A] : 
    ? [B] : m1_pboole(B,A) ),
    file(pboole,m1_pboole),
    []).

fof(idempotence_k2_pboole,axiom,(
    ! [A,B,C] : 
      ( ( m1_pboole(B,A)
        & m1_pboole(C,A) )
     => k2_pboole(A,B,B) = B ) ),
    file(pboole,k2_pboole),
    []).

fof(rc1_funct_1,axiom,(
    ? [A] : 
      ( v1_relat_1(A)
      & v1_funct_1(A) ) ),
    file(funct_1,rc1_funct_1),
    []).

fof(reflexivity_r2_pboole,axiom,(
    ! [A,B,C] : 
      ( ( m1_pboole(B,A)
        & m1_pboole(C,A) )
     => r2_pboole(A,B,B) ) ),
    file(pboole,r2_pboole),
    []).

fof(t15_pboole,axiom,(
    ! [A,B] : 
      ( m1_pboole(B,A)
     => ! [C] : 
          ( m1_pboole(C,A)
         => ! [D] : 
              ( m1_pboole(D,A)
             => ( ( r2_pboole(A,B,C)
                  & r2_pboole(A,C,D) )
               => r2_pboole(A,B,D) ) ) ) ) ),
    file(pboole,t15_pboole),
    []).

fof(t16_pboole,axiom,(
    ! [A,B] : 
      ( m1_pboole(B,A)
     => ! [C] : 
          ( m1_pboole(C,A)
         => ( r2_pboole(A,B,k2_pboole(A,B,C))
            & r2_pboole(A,C,k2_pboole(A,B,C)) ) ) ) ),
    file(pboole,t16_pboole),
    []).

fof(t18_pboole,axiom,(
    ! [A,B] : 
      ( m1_pboole(B,A)
     => ! [C] : 
          ( m1_pboole(C,A)
         => ! [D] : 
              ( m1_pboole(D,A)
             => ( ( r2_pboole(A,B,C)
                  & r2_pboole(A,D,C) )
               => r2_pboole(A,k2_pboole(A,B,D),C) ) ) ) ) ),
    file(pboole,t18_pboole),
    []).