Another operator is the precondition operator, which gives the (weakest) precondition of a state change for a given postcondition.
As the laws are proved in a weakest precondition semantics of rool, correctness of refactoring is ensured by construction.
It is also worth mentioning here that the work of Dijkstra (1976) on weakest precondition calculus is very much related to dynamic logic (and Hoare's logic).
In this paper we investigate how formal software verification systems can be improved by utilising parallel assignment in weakest precondition computations.
In fact, what Dijkstra calls the weakest liberal precondition, denoted wlp(S,Q), is the same as the box operator in dynamic logic: wlp(S,Q) = [S]Q, while his weakest precondition, denoted wp(S,Q), is the total correctness variant of this, meaning that this expression also entails the termination of statement S (cf. Cousot 1990).
A set of programming laws is available for the imperative constructs of this language as well as for its object-oriented features; soundness of the laws is proved against a weakest precondition semantics.
The notion of weakest liberal precondition semantics, introduced by Dijkstra for classical deterministic programs and by McIver and Morgan for probabilistic programs, is generalized to our quantum programs.
However, protection of visual cells from light damage was weaker than after hypoxic preconditioning suggesting that factors in addition to Epo contribute to retinal protection by hypoxia.
Therefore, the difference in the psychological restorative effect may be a result of the precondition in which the original research plot was to some extent managed already as an artificial forest, or by the control condition in which weaker thinning was carried out in this study.
He continued, "although the preconditions for recovery remain in place," prospects for British exports were "weaker than previously expected".
