Temporal Logic of Actions

Temporal logic of actions (TLA) is a logic developed by Leslie Lamport, which combines temporal logic with a logic of actions. It is used to describe behaviours of concurrent systems.Statements in temporal logic of the form , where A is an action and t contains a subset of the variables appearing in A. An action is an expression containing primed and non-primed variables, such as . The meaning of the non-primed variables is the variable's value in this state. The meaning of primed variables is the variable's value in the next state. The above expression means the value of x now, plus the value of x tomorrow times the value of y now, equals the value of y tomorrow.
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