Lexical analyzer Flashcards
1
Q
(Kleene’s theorem) all finite automaton recognize regular language and vice versa
prove that
A
this can be proved by :
1/ convert regex into ε-NFA
2/ convert ε-NFA into DFA
3/ convert DFA into regex
2
Q
DFA minimization
A
after generating the DFA from the regex,
a really big automaton is obtained, consequently, there is the same minimal automaton that accepts the same language L
3
Q
why we can use finite automaton for syntactic analysis
A
because there some simple languages such that L() that are not regular consequently, can not be specified by regex and FA
4
Q
What is the semantic of a grammar
A
it’ is the set of words generated by a grammar
5
Q
what is ambiguous grammar
A
it is a grammar that has more than one derivation tree
