The following code in Scheme is syntactically correct

(define (sumlist   x)

  (cond

    (x == 0)

    (else (+ (car x) (sumlist(cdr   x))))

  )

Given the following automaton 

Which of the sollowing strings are recognized by the automaton 

p^+ = p^*p

The parser takes the lexical units from the lexical analyzer and uses them to construct hierarchical structures called parse trees.

A lexical analyzer is a pattern matcher that isolates the small-scale parts of a program, which are called regular expressions.

The subset construction convert a Regular Expression into a NFA

The following automaton is an example of a DFA