72 ;;Quote: we attach meaning to perceived structures in the meaningless bits of computer memory and the meaningless traces of computer programs

75 ;;Quote: the goal of an operating system is insensitivity to indeterminism; via layers that are insensitive to proceeding layers

75+;;Quote: structure an operating system as layers of insensitive, abstract machines

75 ;;Quote: avoid unordered modules, each implementing a function; difficult to integrate with each other; quadratic growth in complexity

76 ;;Quote: hide interrupts via abstract processors; everything else as cooperating sequential processes

76 ;;Quote: use an interrupting clock to regulate the bottom layer of the operating system

76+;;Quote: code all synchronization explicitly; speed ratios are not available

80 ;;Quote: if a semaphore is zero, processes may be blocked, waiting for a P-operation; a V-operation wakes one of these processes, without starvation

80 ;;Quote: P- and V-operations solve the problem of mutual exclusion

133 ;;Quote: use private and public semaphores to control access to a shared resource; intermediate states for desired access

88 ;;Quote: the dining philosophers problem demonstrates the constructive approach to multiprogramming correctness

88+;;Quote: introduce the intermediate state, 'hungry', to solve the dining philosophers problem

90 ;;Quote: avoid priority inversion by giving priority to processes in a critical section; T.H.E multiprogramming system uses 'red' and 'white' processes

90 ;;Quote: assign user programs to reserved processes; do not charge time spent in critical sections

91 ;;Quote: combine critical regions into a secretary process; invoked, as needed, by its directors; order is undefined