% Mizar problem: t1_numerals,numerals,35,5 
fof(t1_numerals, conjecture, m1_subset_1(k1_xboole_0, k4_ordinal1)).
fof(antisymmetry_r2_hidden, axiom,  (! [A, B] :  (r2_hidden(A, B) =>  ~ (r2_hidden(B, A)) ) ) ).
fof(asymmetry_r2_tarski, axiom,  (! [A, B] :  (r2_tarski(A, B) =>  ~ (r2_tarski(B, A)) ) ) ).
fof(d11_ordinal1, axiom,  (! [A] :  (A=k4_ordinal1 <=>  (r2_tarski(k1_xboole_0, A) &  (v4_ordinal1(A) &  (v3_ordinal1(A) &  (! [B] :  (v3_ordinal1(B) =>  ( (r2_tarski(k1_xboole_0, B) & v4_ordinal1(B))  => r1_tarski(A, B)) ) ) ) ) ) ) ) ).
fof(d1_subset_1, axiom,  (! [A] :  (! [B] :  ( ( ~ (v1_xboole_0(A))  =>  (m1_subset_1(B, A) <=> r2_tarski(B, A)) )  &  (v1_xboole_0(A) =>  (m1_subset_1(B, A) <=> v1_xboole_0(B)) ) ) ) ) ).
fof(dt_k1_xboole_0, axiom, $true).
fof(dt_k4_ordinal1, axiom, $true).
fof(dt_m1_subset_1, axiom, $true).
fof(existence_m1_subset_1, axiom,  (! [A] :  (? [B] : m1_subset_1(B, A)) ) ).
fof(redefinition_r2_tarski, axiom,  (! [A, B] :  (r2_tarski(A, B) <=> r2_hidden(A, B)) ) ).
fof(reflexivity_r1_tarski, axiom,  (! [A, B] : r1_tarski(A, A)) ).
fof(t6_boole, axiom,  (! [A] :  (v1_xboole_0(A) => A=k1_xboole_0) ) ).
fof(t7_boole, axiom,  (! [A] :  (! [B] :  ~ ( (r2_tarski(A, B) & v1_xboole_0(B)) ) ) ) ).
fof(t8_boole, axiom,  (! [A] :  (! [B] :  ~ ( (v1_xboole_0(A) &  ( ~ (A=B)  & v1_xboole_0(B)) ) ) ) ) ).
