% Mizar problem: t66_zfmisc_1,zfmisc_1,842,41 
fof(t66_zfmisc_1,conjecture,(
    ! [A,B] : ~ ( k4_xboole_0(A,k1_tarski(B)) = k1_xboole_0
      & A != k1_xboole_0
      & A != k1_tarski(B) ) ),
    inference(mizar_bg_added,[status(thm)],[dt_k1_tarski,dt_k1_xboole_0,dt_k4_xboole_0,fc1_xboole_0,l4_zfmisc_1,rc1_xboole_0,rc2_xboole_0,reflexivity_r1_tarski,t37_xboole_1]),
    [file(zfmisc_1,t66_zfmisc_1)]).

fof(dt_k1_tarski,axiom,(
    $true ),
    file(tarski,k1_tarski),
    []).

fof(dt_k1_xboole_0,axiom,(
    $true ),
    file(xboole_0,k1_xboole_0),
    []).

fof(dt_k4_xboole_0,axiom,(
    $true ),
    file(xboole_0,k4_xboole_0),
    []).

fof(fc1_xboole_0,axiom,(
    v1_xboole_0(k1_xboole_0) ),
    file(xboole_0,fc1_xboole_0),
    []).

fof(l4_zfmisc_1,axiom,(
    ! [A,B] : 
      ( r1_tarski(A,k1_tarski(B))
    <=> ( A = k1_xboole_0
        | A = k1_tarski(B) ) ) ),
    file(zfmisc_1,l4_zfmisc_1),
    []).

fof(rc1_xboole_0,axiom,(
    ? [A] : v1_xboole_0(A) ),
    file(xboole_0,rc1_xboole_0),
    []).

fof(rc2_xboole_0,axiom,(
    ? [A] : ~ v1_xboole_0(A) ),
    file(xboole_0,rc2_xboole_0),
    []).

fof(reflexivity_r1_tarski,axiom,(
    ! [A,B] : r1_tarski(A,A) ),
    file(tarski,r1_tarski),
    []).

fof(t37_xboole_1,axiom,(
    ! [A,B] : 
      ( k4_xboole_0(A,B) = k1_xboole_0
    <=> r1_tarski(A,B) ) ),
    file(xboole_1,t37_xboole_1),
    []).