1. A computer-performed method performed by a general-purpose computer system that modifies a netlist describing a logic design, the method comprising: reading a simulation output from a simulation performed on the logic design, wherein the simulation output contains states having values dependent on symbolic values introduced as inputs to the logic design in the simulation; determining that the symbolic values reveal relationships or behaviors within the logic design that indicate that the logic design can be simplified or reduced; and modifying the netlist to simplify or reduce the netlist in accordance with a result of the determining.