The closure statement : a programming language construct allowing ultraconcurrent execution

The closure statement is the basic statement when programming with assooons Its execution may revolve a very high degree of concurrency The state of a computation is represented as a set of assocmns. The closure statement transforms this set into a closure thereof. The defimtmn and the mathematical properUes of these closures are presented Dljkstra's weakest precondmons are used to define the semanUcs of the closure statement In terms of the closure concept The theorems on closures are then translated into theorems on closure statements It is shown, by means of four examples, how these theorems can be used for the construction of correct assocmn programs.