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IIST and UNU - UNU-IIST - United Nations University

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Temporal logic of resource cumulation 8<br />

Examples of temporal logics<br />

The amount of time that a computation consumes corresponds to the cumulator RTime. A<br />

real-time specification is a predicate on a typed modal variable t ∈ [0, ∞] that denotes time <strong>and</strong><br />

an untyped auxiliary variable s that denotes the system’s state at the time. We let T denote<br />

the space of such specifications. Since addition is commutative i.e. a + b = b + a, it makes no<br />

difference whether time is extended from the left-h<strong>and</strong> side or the right-h<strong>and</strong> side. For example,<br />

e t = x described a system’s temporature growing exponentially over time.<br />

Intervals within a time domain form the cumulator Interval . A specification on intervals is<br />

a predicate on a variable i ∈ I that denotes the interval <strong>and</strong> an auxiliary variable x that denotes<br />

some system feature related to the interval. We let I denote the space of all temporal<br />

specifications on intervals. An interval can be extended from either left-h<strong>and</strong> side or right-h<strong>and</strong><br />

side.<br />

Traces of elements of X form a cumulator Trace(X) . A trace specification is a predicate on<br />

a single variable tr ∈ X † . We let S denote the space of trace specifications. For example, the<br />

specification |S|

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