LECTURE 4
FORMAL METHODS
| Operational Methods Generate Behaviors Automata Finite State Machines Extended State Machines Petri-Nets |
Descriptive Methods Describe Properties ER Diagrams Grammars Regular Expressions Logic Algebraic Specifications |
State-Based Schemes
A. Finite State Machines
Basic Machine: (Q, I, d, q0, F)
Q = {states}, I = {symbols}, q0 e Q, F Í Q
d: Q ´ I ® Q
Gate Example
Limitations
B. Extended State Machines
Transition: G ® I/A/O
G - guard I - input A - action O - output
Gate Controller Example
Further Extensions: Concurrency, Time