When and how to strengthen assumptions in contract-based reasoning

Determine the conditions under which strengthening the assumption part of an assume–guarantee contract should be used as an alternative to weakening the goal or guarantee property in response to environmental changes, and devise a precise formal method for performing such assumption strengthening within contract-based reasoning frameworks.

Background

The paper proposes a counterexample-guided technique to iteratively weaken logical properties when desired guarantees fail due to system degradation or environmental changes, initially for propositional logic. It highlights that not all weakenings are useful and introduces a critical property to bound the weakening.

Beyond weakening guarantees, contract-based (assume–guarantee) reasoning offers an alternative: strengthen the assumption side of the contract to maintain validity under changed environments. The authors explicitly note uncertainty about when this alternative is appropriate and how to carry it out, positioning it as key to understanding the impact of weakening or strengthening on other components and system-level properties (related to RQ2).