% Mizar problem: t1_glib_009,glib_009,51,5 
fof(t1_glib_009, conjecture,  (! [A] :  (! [B] :  (r1_tarski(B, A) => k6_subset_1(A, k6_subset_1(A, B))=B) ) ) ).
fof(commutativity_k3_xboole_0, axiom,  (! [A, B] : k3_xboole_0(A, B)=k3_xboole_0(B, A)) ).
fof(dt_k1_zfmisc_1, axiom, $true).
fof(dt_k3_xboole_0, axiom, $true).
fof(dt_k4_xboole_0, axiom, $true).
fof(dt_k6_subset_1, axiom,  (! [A, B] : m1_subset_1(k6_subset_1(A, B), k1_zfmisc_1(A))) ).
fof(dt_m1_subset_1, axiom, $true).
fof(existence_m1_subset_1, axiom,  (! [A] :  (? [B] : m1_subset_1(B, A)) ) ).
fof(idempotence_k3_xboole_0, axiom,  (! [A, B] : k3_xboole_0(A, A)=A) ).
fof(redefinition_k6_subset_1, axiom,  (! [A, B] : k6_subset_1(A, B)=k4_xboole_0(A, B)) ).
fof(reflexivity_r1_tarski, axiom,  (! [A, B] : r1_tarski(A, A)) ).
fof(t28_xboole_1, axiom,  (! [A] :  (! [B] :  (r1_tarski(A, B) => k3_xboole_0(A, B)=A) ) ) ).
fof(t3_subset, axiom,  (! [A] :  (! [B] :  (m1_subset_1(A, k1_zfmisc_1(B)) <=> r1_tarski(A, B)) ) ) ).
fof(t48_xboole_1, axiom,  (! [A] :  (! [B] : k4_xboole_0(A, k4_xboole_0(A, B))=k3_xboole_0(A, B)) ) ).
