A refinement system automatically identifies whether a detected error in a target system during abstract interpretation is a false error or a true error and adjusts the interpretation to prevent the false error. The target system is represented as a transition system with an initial state and state transitions and a specification that the target system is to satisfy. The refinement system iteratively performs steps of the abstract interpretation using a widening operator. When the state of a step does not satisfy the specification, the refinement system identifies a step whose widening operator was the source of the state that did not satisfy the specification and applies a more precise operator that eliminates the problem with the widening. The refinement system then starts re-performing the steps starting at that step.