1. Laplante + Skubic 1 Formal methods in software specification  Finite state machines  Statecharts  Propositional logic

2. Laplante + Skubic 2 Finite state machines

3. Laplante + Skubic 3 Finite state machines event current stateop_opop_calerror calibrationoperationalcalibrationdiagnostic operationalcalibrationdiagnostic operational calibrationdiagnostic

4. Laplante + Skubic 4 op_op/a1 Calibration Operational c1 c2 a1a2 o1 o2 a1a2 Statecharts

5. Laplante + Skubic 5 Propositional Logic Consider the following excerpt from the Software Requirements Specification for the nuclear monitoring system. 1.1 If interrupt A arrives, then task B stops executing. 1.2 Task A begins executing upon arrival of interrupt A. 1.3 Either Task A is executing and Task B is not, or Task B is executing and Task A is not, or both are not executing. These requirements can be formalized by rewriting each in terms of their component propositions, namely: p: interrupt A arrives q: task B is executing r: task A is executing

6. Laplante + Skubic 6 Propositional Logic Truth table used to check the consistency of the set of three requirements.