Contracts are behavioural descriptions of Web services. We devise a theory of contracts that formalises the compatibility of a client to a service, and the safe replacement of a s...
When restricted to proving q i formulas, the quantified propositional proof system G i is closely related to the b i theorems of Buss's theory Si 2. Namely, G i has polynomial...
It is argued that Ginsberg's Possible Worlds Approach to counterfactual implication suffers from a number of defects which are the result of confusing proof theory and model ...