% Mizar problem: t21_zfmisc_1,zfmisc_1,339,29 
fof(t21_zfmisc_1,conjecture,(
    ! [A,B] : 
      ( k4_xboole_0(k1_tarski(A),k1_tarski(B)) = k1_xboole_0
     => A = B ) ),
    inference(mizar_bg_added,[status(thm)],[antisymmetry_r2_hidden,d1_tarski,dt_k1_tarski,dt_k1_xboole_0,dt_k4_xboole_0,fc1_xboole_0,l36_zfmisc_1,rc1_xboole_0,rc2_xboole_0]),
    [file(zfmisc_1,t21_zfmisc_1)]).

fof(antisymmetry_r2_hidden,axiom,(
    ! [A,B] : 
      ( r2_hidden(A,B)
     => ~ r2_hidden(B,A) ) ),
    file(hidden,r2_hidden),
    []).

fof(d1_tarski,axiom,(
    ! [A,B] : 
      ( B = k1_tarski(A)
    <=> ! [C] : 
          ( r2_hidden(C,B)
        <=> C = A ) ) ),
    file(tarski,d1_tarski),
    []).

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(l36_zfmisc_1,axiom,(
    ! [A,B] : 
      ( k4_xboole_0(k1_tarski(A),B) = k1_xboole_0
    <=> r2_hidden(A,B) ) ),
    file(zfmisc_1,l36_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),
    []).