Let G be the following context-free grammar S > Ваа | С А > аЛ|а В БВа | b C dC A|d a) For each variable, derive its CHAIN set. CHAIN(S)-{ CHAIN (A)={ CHAIN(B) { CHAIN(C) { } b) Give a grammar equivalent to G that does not contain chain rules. Follow the construction as discussed in class

Let G be the following context-free grammar S > Ваа | С А > аЛ|а В БВа | b C dC A|d a) For each variable, derive its CHAIN set. CHAIN(S)-{ CHAIN (A)={ CHAIN(B) { CHAIN(C) { } b) Give a grammar equivalent to G that does not contain chain rules. Follow the construction as discussed in class

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Consider the context-free grammar G = (V, T, S, P), where V = {S, A}, T = {a, b}, and P consists of S → aSb | aAb, A → aA | λ. a. Show the derivation tree resulting from top-down parsing of the string aaaabb. b. Show the leftmost derivation of the string aaaabb.
Question 2-Context-free Grammars Consider the alphabet = {A, V., (,), x, y, z) and the following grammar G = (V,E, R, F), defined by the rules: F (FAF) | (FVF) | (F) | P (a) Identify the set of variables and the set of terminal symbols of G. (b) Identify three words (of lengths between 10 and 20) that can be generated by the above grammar and show their derivations. (c) Consider a modified grammar G', where we remove the brackets '(' and ')' from the alphabet and the derivation rules. That is we set Σ'= {A, V., x, y, z) and we remove all occurrences of brackets in the derivation rules. Show that there are words that are derived ambiguously in G'
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