Data is globally accessible and nothing prevents one rule overwriting the result of another rule.
Such mechanisms are the definition of circular data-objects of unbounded size; assignment; memoization of the results of function application; or of course the overwriting of a closure by its value.
He changed now directly by overwriting the old figures, first the 39 into a 40, correcting correspondingly the differences 13'/2 into 14'/2 and 14'/2 into 13'/2.
In almost all cases a thunk will be entered and updated between garbage collections, so that no space improvement is gained by overwriting with a black hole.
Updating a node may be performed by overwriting it with either a new node, or with an indirection pointing to an existing node.
More precisely, naively sharing or-parallel work might result in overwriting suspended stacks.
As a result, there were almost no problems with memory leaks or overwriting during the development of the system.
Overwriting models of this sort seem possible for the description of memory for sequential stimuli but not simultaneous arrays.
