Which of the following are decidable ?
1. whether the intersection of two regular language is infinite.
2. whether a give context free language is regular
3. whether two push down automata accept the same language.
4. whether a given grammar is context free

Related MCQs

• Which of the following are decidable? I. Whether the intersection of two regular languages is infinite II. Whether a given context-free language is regular III. Whether two push-down automata accept the same language IV. Whether a given grammar is context-free
• Which of the following problems are decidable? 1) Does a given program ever produce an output? 2) If L is a context-free language, then is L’ (complement of L) also context-free? 3) If L is a regular language, then is L’ also regular? 4) If L is a recursive language, then, is L’ also recursive?
• Consider the following decision problems: (P1) Does a given finite state machine accept a given string (P2) Does a given context free grammar generate an infinite number of stings Which of the following statements is true?
• Consider the following expression grammar. The seman-tic rules for expression calculation are stated next to each grammar production. E → number E.val = number. val | E '+' E E(1).val = E(2).val + E(3).val | E '×' E E(1).val = E(2).val × E(3).val The above grammar and the semantic rules are fed to a yacc tool (which is an LALR (1) parser generator) for parsing and evaluating arithmetic expressions. Which one of the following is true about the action of yacc for the given grammar?
• Match all items in Group 1 with correct options from those given in Group 2. List I List II P. Regular Expression 1. Syntax analysis Q. Push down automata 2. Code Generation R. Dataflow analysis 3. Lexical analysis S. Register allocation 4. Code optimization
• Consider the following grammar. S -> S * E S -> E E -> F + E E -> F F -> id Consider the following LR(0) items corresponding to the grammar above. (i) S -> S * .E (ii) E -> F. + E (iii) E -> F + .E Given the items above, which two of them will appear in the same set in the canonical sets-of-items for the grammar?
• Consider the following two statements: P: Every regular grammar is LL(1) Q: Every regular set has a LR(1) grammar Which of the following is TRUE?
• Consider the following statements related to compiler construction : I. Lexical Analysis is specified by context-free grammars and implemented by pushdown automata. II. Syntax Analysis is specified by regular expressions and implemented by finite-state machine. Which of the above statement(s) is/are correct?
• Let L1 be a regular language, L2 be a deterministic context-free language and L3 a recursively enumerable, but not recursive, language. Which one of the following statements is false?
• The regular grammar for the language L = {anbm | n + m is even} is given by