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FORMAL LANGUAGES AND COMPILERS prof.s Luca Breveglieri and Angelo Morzenti Exam of Mon 18 JUNE 2018 - Part Theory WITH SOLUTIONS - FOR TEACHING PURPOSES HERE THE SOLUTIONS ARE WIDEL Y COMMENTED LAST + FIRST NAME: (capital letters please) MATRICOLA: SIGNATURE: (or PERSON CODE) INSTRUCTIONS - READ CAREFULLY: • The exam is in written form and consists of two parts: 1. Theory (80%): Syntax and Semantics of Languages – regular expressions and finite automata – free grammars and pushdown automata – syntax analysis and parsing methodologies – language translation and semantic analysis 2. Lab (20%): Compiler Design by Flex and Bison • To pass the exam, the candidate must succeed in both parts (th eory and lab), in one call or more calls separately, but within one year (12 months ) between the two parts. • To pass part theory, the candidate must answer the mandatory (not optional) ques- tions; notice that the full grade is achieved by answering th e optional questions. • The exam is open book: textbooks and personal notes are permi tted. • Please write in the free space left and if necessary continue on the back side of the sheet; do not attach new sheets and do not replace the existin g ones. • Time: part lab 60m - part theory 2h.15m 1 Regular Expressions and Finite Automata 20% 1. Consider the nondeterministic automaton A over the three-letter alphabet { a, b, c }: 1 3 2 A → → a b c ε Answer the following questions: (a) List all the strings of length from 0 to 4 (0 and 4 included) that are accepted by automaton A. Say if automaton A is ambiguous or not and explain why. (b) Cut the spontaneous transition of automaton A, so that after cutting the result is deterministic. Say if the result is minimal and if necessa ry minimize it (call it A′). Verify the correctness of A′ with…