Embodiments of the invention are directed to a computer-implemented method of logic verification. The method includes obtaining a netlist of a circuit comprising a plurality of observable gates. A first observable gate is grouped together with a second observable gate based on a portion of a fan-in logic of the first observable gate being equal to a portion of a fan-in logic of the second observable gate. The group is expanded by including a third observable gate, based on a first strongly connected component (SCC) in the group having a similarity greater than a first threshold to a second SCC in the fan-in logic of the third observable gate. The group is further expanded by including a fourth observable gate, based on the distance of a portion of the fan-in logic of the fourth observable gate from a fan-in logic of at least one observable gate in the group of observable gates.