25 lines
1,005 B
Markdown
25 lines
1,005 B
Markdown
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A (finite non-deterministic) automaton is a quintuple M = (Q,Act,q0,F,T), where:
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- Q is the set of states
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- Act is the set of actions
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- q0 is the starting state
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- F is the set of final states
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- T is the transition relation (T ⊆ Q × Act × Q)
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Automata Behaviour: language equivalence
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(where L(M) is the set of all the sequences of input characters that bring the automaton M from its starting state to a final one)
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>[!note] Language equivalence
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>M1 and M2 are *language equivalent* if and only if L(M1)=L(M2)
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By considering the starting states as also final, they both generate the same language, i.e.:
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$$(20.(tea + 20.coffee))∗ = (20.tea + 20.20.coffee)∗$$
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But, do they behave the same from the point of view of an external observer??
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The essence of the difference is WHEN the decision to branch is taken
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- language equivalence gets rid of branching points
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- it is too coarse for our purposes!
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