Using the grammars, draw trees for the expressions given, then answer the questions. There are tools available for drawing trees, but you may simply draw them by hand, as long as they are neat. Then scan them into a single document and upload in Canvas. Grammar 1 Grammar 2 Grammar 3 → - | → / | → ()| →A | B | C → - | → / | → ()| → A | B | C → / | → - | → ()| → A |B | C 1. Derive parse trees for the expression A-B/C a. using Grammar 1 b. using Grammar 2 C. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why? 2. Derive parse trees for the expression A-B-C a. using Grammar 1 b. using Grammar 2 c. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why? 3. Derive parse trees for the expression (A-B)/C a. using Grammar 1 b. using Grammar 2 c. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why?

Using the grammars, draw trees for the expressions given, then answer the questions. There are tools available for drawing trees, but you may simply draw them by hand, as long as they are neat. Then scan them into a single document and upload in Canvas. Grammar 1 Grammar 2 Grammar 3 → - | → / | → ()| →A | B | C → - | → / | → ()| → A | B | C → / | → - | → ()| → A |B | C 1. Derive parse trees for the expression A-B/C a. using Grammar 1 b. using Grammar 2 C. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why? 2. Derive parse trees for the expression A-B-C a. using Grammar 1 b. using Grammar 2 c. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why? 3. Derive parse trees for the expression (A-B)/C a. using Grammar 1 b. using Grammar 2 c. using Grammar 3 Are any of these parse trees 'better' than any of the others for this expression? Why?

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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Given the following BNF grammar <go> → <go>@<excellent> <go> → start | finish <excellent> → . <excellent> | up | down Write the derivation and draw the parse trees of the following sentences: start@down@.up
Given the following BNF grammar <go> → <go>@<good> <go> → start | finish <good> → . <good> | up | down Write the derivation and draw the parse trees of the following sentences: start@down@.up
Give the derivation tree for ((a+b)∗c+d, using the grammar in Example 5.12. EXAMPLE 5.12 To rewrite the grammar in Example 5.11 we introduce new variables, taking V as {E, T, F, I}, and replacing the productions with E→T,T→F,F→I,E→E+T,T→T*F,F→(E),I→a|b|c.E→T,T→F,F→I,E→E+T,T→T*F,F→(E),I→a|b|c. A derivation tree of the sentence a + b ∗ c is shown in Figure 5.6. No other derivation tree is possible for this string: The grammar is unambiguous. It is also equivalent to the grammar in Example 5.11. It is not too hard to justify these claims in this specific instance, but, in general, the questions of whether a given context-free grammar is ambiguous or whether two given context-free grammars are equivalent are very difficult to answer. In fact, we will later show that there are no general algorithms by which these questions can always be resolved.
Grammar and its application to FractalsLet G=(N,T,P,∑) where ∑ is the start symbol, N = {D}, T = {d, r, l}, andP = {∑→D, D→DrDllDrD, D → d} 1. Give the most specific type of grammar G.2. Show the leftmost derivation sequence of the string drdlldrd, (i.e. When deriving a new sentential form, always replace one Nonterminal at a time and always replace the leftmost Nonterminal)3. Suppose d is an abstraction of a command to draw a straight line of fixed length in the current direction, r is an abstraction of a command to turn right by 60 degrees, and l is an abstraction of a command to turn left by 60 degrees. Assuming that you are to start from a point and that the starting direction is to proceed horizontally to the right, show the figure represented by the generated string drdlldrd.4. The string drdlldrdrdrdlldrdlldrdlldrdrdrdlldrd can also be generated. Assuming that you are to start from a point and that the starting direction is to proceed horizontally to the right, show the figure…
Consider the ambiguous grammar S → ABS | ABA → aA | λB → bB | λ What is the shortest string in L(S) other than λ that can be used to show the grammar is ambiguous? Write the string without any spaces or quotation marks. Now show the grammar ambiguous by giving two derivations for the string (each derivation should have a particular important property). Give the two shortest derivations you can find, writing the shorter one in the first box. Your derivations should begin with S, end with your chosen string, and only make one substitution per step. Do not include any spaces, quotes, or lambdas in your answer. Use the ">" character to represent the right arrow. For example, S>aSb>ab might be a legal derivation for a string in another language.
Computer Science Consider the following two grammars with alphabet a and b i. (b*ab*a)*b* ii. (b*ab*a)*b*(b*ab*a)*b* Are there any strings are generated by one of the grammars and cannot be generated by the other? If there are more than one such string, how do you describe them.
Consider the Grammarbexpr ( bexpr or bterm | btermbterm ( bterm and bfactor | bfactorbfactor ( not bfactor | (bexpr) | true | falseConstruct a parse tree for the sentence not(true or false)
We are given the following attribute grammar.T → a {T.v = 0}T → b {T.v = 1} T → c {T.v = 2}T → T a {T0.v = T1.v * 3}T → T b {T0.v = T1.v * 3 + 1}T → T c {T0.v = T1.v * 3 + 2} Draw and annotated parse tree for the input "b a a c".
Consider the grammar G below in the input alphabet {num, *, /, -}, with non-terminal leading S' in rule 1. S'→S$ S→E - F F→E * E E→num E→num / num a) Build the G grammar automaton. Is this grammar LR(0)? b) If G is not LR(0), list the items present in the DFA state where the conflict occurs. c) Is this grammar SLR? d) If G is SLR, write the non-terminal follow that resolves the LR(0) conflict. (Separate the items in the set with “:”. Ex: a:b )
Consider the grammar G below in the input alphabet {x, y, z, *}, with leading non-terminal S' in rule 1. S'→S $ S → E * F S → F E → x E → z F y F F → E a) Build the LR(1) automaton of grammar G. Is this grammar LR(1)? b) List the LR(1) items in the last automaton state reached (without performing reductions on the last character) when the input is: x* z zx zxy For this question, indicate the lookahead and the top of the stack, it is also necessary to list the states in the same order as the grammar rules. Also, list the lookaheads in the order {?, $, x, y, z, *} c) Check if G is LALR. If so, answer with the number of states eliminated in relation to the previous automaton. If not, answer with -1
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.
Prove that the grammar below is ambiguous or not with given the sentence c@dc (showing the step) <A> → <A><A> <A> → <B>@ | <@><B> | <B> <B> → a | b | c | d After that, change the grammar so that the tree only expand to the left (left associativity) and draw the parse tree.