What is an ambiguous grammar give an example?
A Grammar that makes more than one Leftmost Derivation (or Rightmost Derivation) for the similar sentence is called Ambiguous Grammar. Example − Verify whether the following Grammar is Ambiguous or Not. For string id + id * id, there exist two parse trees.
How do you determine if a grammar is ambiguous?
A grammar is said to be ambiguous if there exists more than one leftmost derivation or more than one rightmost derivation or more than one parse tree for the given input string. If the grammar is not ambiguous, then it is called unambiguous.
How do you make an ambiguous grammar unambiguous?
To convert ambiguous grammar to unambiguous grammar, we will apply the following rules: 1. If the left associative operators (+, -, *, /) are used in the production rule, then apply left recursion in the production rule….The unambiguous grammar is:
- S → aXY | bYZ | ε
- Z → aZ | a.
- X → aXY | a | ε
- Y → bYZ | b | ε
What is ambiguity in programming?
Data Structure AlgorithmsComputer ScienceComputers. A grammar is said to be ambiguous if there exists more than one left most derivation or more than one right most derivation or more than one parse tree for a given input string. If the grammar is not ambiguous then we call it unambiguous grammar.
Is the following grammar is ambiguous S -> Asbs Bsas ∈?
Detailed Solution The correct answer is option 4. A is ambiguous because λ can be generated using leftmost derivation having two different parse trees with an empty string. B is ambiguous grammar with string abab.
Which is ambiguous grammar?
In computer science, an ambiguous grammar is a context-free grammar for which there exists a string that can have more than one leftmost derivation or parse tree, while an unambiguous grammar is a context-free grammar for which every valid string has a unique leftmost derivation or parse tree.
Which of the following grammar S is are ambiguous i’s → AA → BB → є II S → AA → bb a є B → A є III S → AA BA →?
The correct answer is option 4. A is ambiguous because λ can be generated using leftmost derivation having two different parse trees with an empty string.
What is ambiguous and unambiguous grammar explain with example?
A context-free grammar is called ambiguous grammar if there exists more than one derivation tree or parse tree. Example – S -> S + S / S * S / S / a. 2. Unambiguous Grammar : A context-free grammar is called unambiguous grammar if there exists one and only one derivation tree or parse tree.
How do you solve the problem of ambiguous grammar?
Methods To Remove Ambiguity-
- By fixing the grammar.
- By adding grouping rules.
- By using semantics and choosing the parse that makes the most sense.
- By adding the precedence rules or other context sensitive parsing rules.
Which of the following grammar is unambiguous S 0s s0 0?
The grammar is unambiguous. First, we can show that the language of the grammar is 0*(0 + 1*1) ; that is, the language of any number of 0 s, followed either by a single 0 or by any non-empty string of 1 s.
Which is the ambiguous grammar MCQ?
The correct answer is option 4. The grammar S → SS | a is ambiguous grammar. It generates two parse trees with string aaa. The grammar S → 0S1 | 01S |e is ambiguous.
What is leftmost and rightmost derivation?
Leftmost derivation − A leftmost derivation is obtained by applying production to the leftmost variable in each step. Rightmost derivation − A rightmost derivation is obtained by applying production to the rightmost variable in each step.