As good as gold [circuit design]

Simulation is a natural outgrowth of the hardware breadboard that preceded engineering workstations and commercial design automation tools. For the breadboard, simulation substitutes software: a netlist or a model in a hardware description language (HDL) represents the design, then the simulator automatically applies stimuli to the model´s inputs and captures the response of the model´s outputs. Using such a system, designers show that a design meets functional requirements by trying many different operational scenarios. However, as designs grow larger, the time required to simulate each function grows exponentially. The paper discusses the use of formal verification approaches for logic design