% Mizar ND problem: t189_orders_1,orders_1,2226,36 fof(involutiveness_k4_relat_1,theorem,( ! [A] : ( v1_relat_1(A) => k4_relat_1(k4_relat_1(A)) = A ) ), file(relat_1,k4_relat_1), [interesting(0.9),axiom,file(relat_1,k4_relat_1)]). fof(dt_k4_relat_1,axiom,( ! [A] : ( v1_relat_1(A) => v1_relat_1(k4_relat_1(A)) ) ), file(relat_1,k4_relat_1), [interesting(0.9),axiom,file(relat_1,k4_relat_1)]). fof(l154_orders_1,plain,( ! [A] : ( v1_relat_1(A) => ! [B] : ( r1_relat_2(A,B) => r1_relat_2(k4_relat_1(A),B) ) ) ), file(orders_1,l154_orders_1), [interesting(0.9),axiom,file(orders_1,l154_orders_1)]). fof(t189_orders_1,theorem,( ! [A] : ( v1_relat_1(A) => ! [B] : ( r1_relat_2(A,B) => r1_relat_2(k4_relat_1(A),B) ) ) ), inference(mizar_by,[status(thm),assumptions([])],[involutiveness_k4_relat_1,dt_k4_relat_1,l154_orders_1]), [interesting(1),file(orders_1,t189_orders_1),[file(orders_1,t189_orders_1)]]).