$\DeclareMathOperator{\Rad}{Rad} \DeclareMathOperator{\End}{End} \DeclareMathOperator{\Ker}{Ker} \DeclareMathOperator{\Imm}{Im} \DeclareMathOperator{\I}{Im} \DeclareMathOperator{\Hom}{Hom} \DeclareMathOperator{\op}{op} \DeclareMathOperator{\Mat}{Mat} \DeclareMathOperator{\Irr}{Irr} \DeclareMathOperator{\Id}{Id} \DeclareMathOperator{\Arg}{Arg} \DeclareMathOperator{\im}{Im} \DeclareMathOperator{\re}{Re} \newenvironment{framed}{}{}$