% Mizar problem: t86_enumset1,enumset1,989,5 
fof(t86_enumset1, conjecture,  (! [A] :  (! [B] :  (! [C] :  ~ ( ( ~ (A=B)  &  ( ~ (A=C)  &  ~ (k4_xboole_0(k1_enumset1(A, B, C), k1_tarski(A))=k2_tarski(B, C)) ) ) ) ) ) ) ).
fof(antisymmetry_r2_hidden, axiom,  (! [A, B] :  (r2_hidden(A, B) =>  ~ (r2_hidden(B, A)) ) ) ).
fof(commutativity_k2_tarski, axiom,  (! [A, B] : k2_tarski(A, B)=k2_tarski(B, A)) ).
fof(d10_xboole_0, axiom,  (! [A] :  (! [B] :  (A=B <=>  (r1_tarski(A, B) & r1_tarski(B, A)) ) ) ) ).
fof(d1_enumset1, axiom,  (! [A] :  (! [B] :  (! [C] :  (! [D] :  (D=k1_enumset1(A, B, C) <=>  (! [E] :  (r2_hidden(E, D) <=>  ~ ( ( ~ (E=A)  &  ( ~ (E=B)  &  ~ (E=C) ) ) ) ) ) ) ) ) ) ) ).
fof(d1_tarski, axiom,  (! [A] :  (! [B] :  (B=k1_tarski(A) <=>  (! [C] :  (r2_hidden(C, B) <=> C=A) ) ) ) ) ).
fof(d2_tarski, axiom,  (! [A] :  (! [B] :  (! [C] :  (C=k2_tarski(A, B) <=>  (! [D] :  (r2_hidden(D, C) <=>  (D=A | D=B) ) ) ) ) ) ) ).
fof(d3_tarski, axiom,  (! [A] :  (! [B] :  (r1_tarski(A, B) <=>  (! [C] :  (r2_hidden(C, A) => r2_hidden(C, B)) ) ) ) ) ).
fof(d5_xboole_0, axiom,  (! [A] :  (! [B] :  (! [C] :  (C=k4_xboole_0(A, B) <=>  (! [D] :  (r2_hidden(D, C) <=>  (r2_hidden(D, A) &  ~ (r2_hidden(D, B)) ) ) ) ) ) ) ) ).
fof(dt_k1_enumset1, axiom, $true).
fof(dt_k1_tarski, axiom, $true).
fof(dt_k2_tarski, axiom, $true).
fof(dt_k4_xboole_0, axiom, $true).
fof(reflexivity_r1_tarski, axiom,  (! [A, B] : r1_tarski(A, A)) ).
