Non-well-separation (NWS) is a known quality issue in specifications for reactive synthesis. The problem of NWS occurs when the synthesized system can avoid satisfying its guarantees by preventing the environment from being able to satisfy its assumptions.

In this work we present two contributions to better deal with NWS. First, we show how to synthesize systems that avoid taking advantage of NWS, i.e., do not prevent the satisfaction of any environment assumption, even if possible. Second, we propose a set of heuristics for fast detection of NWS. Evaluation over benchmarks from the literature shows the effectiveness and significance of our work.