NP-Complete Language Criterion for P = NP applied Bode Sensitivity Integral applied Separation Principle for Infinite-Horizon Average-Cost LQG Control applied Set Cover NP-Completeness Theorem applied Kalman-Bucy Filter Theorem applied Closure of Polynomial Time Under Polynomial-Time Many-One Reductions applied Duality of Controllability and Observability Gramians applied NP-Completeness of Subset Sum applied