Some aspects provide determination of a function to rectify functional differences between netlist G1 and netlist G2 having inputs V. The determination may include determination of a signal s of netlist G1 that can be re-synthesized so as to correct the functional differences between netlist G1 and netlist G2, assignment of respective static values to a first plurality of inputs V, assignment of respective initial values to a second plurality of inputs V, determination of a first function based on the assigned static values, the assigned initial values, a first error function reflecting the difference between outputs of netlist G1 and netlist G2 for each vector of inputs V in a case that s equals 0, and a second error function reflecting the difference between the outputs of netlist G1 and netlist G2 for each vector of inputs V in a case that s equals 1. Also included may be determination of whether the first function rectifies the functional differences between netlist G1 and netlist G2, assignment, if it is determined that the first function does not rectify the functional differences, of respective next values to the second plurality of inputs, and determination of a second function based on the first function, the assigned static values, the assigned next values, the first error function, and the second error function.