let G be _Graph; :: thesis: (G .allInducedSG()) /\ (G .allSpanningSG()) = {(G | _GraphSelectors)}
now :: thesis: for x being object holds
( ( x in (G .allInducedSG()) /\ (G .allSpanningSG()) implies x = G | _GraphSelectors ) & ( x = G | _GraphSelectors implies x in (G .allInducedSG()) /\ (G .allSpanningSG()) ) )
end;
hence (G .allInducedSG()) /\ (G .allSpanningSG()) = {(G | _GraphSelectors)} by TARSKI:def 1; :: thesis: verum