Czyli \inf\left\{ \emptyset,\emptyset\right\}=\sup\left\{ \emptyset,\emptyset\right\}=\emptyset , \inf\left\{ \emptyset,\left\{ 1\right\} \right\} =\emptyset , \sup\left\{ \emptyset,\left\{ 1\right\} \right\} =\left\{ 1\right\} , \inf\left\{ \left\{ 1\right\} ,\left\{ 0,1\right\} \right\} =\left\{ ...