The document discusses syntax analysis in compilers. It defines syntax as the arrangement of words and phrases to create meaningful sentences. The syntax analyzer or parser checks the stream of tokens for grammatical correctness according to the language's grammar. It determines if the input is well-formed syntactically. The parser ensures sentences in a program abide by the syntax of the language and detects any errors. The document also provides examples of English and programming language syntax and defines key concepts related to context-free grammars.

1. Topic
Syntax Analyzer

2. Complier Phases

3. What is Syntax
The arrangement of words and phrases to create meaningful sentences.
 “He wrote the program”. The arrangement of the sentence can be described using
grammar syntax of English language.

4. Syntax Analyzer
The parser checks the stream of words (tokens) and their parts of speech for
grammatical correctness. It determines if the input is syntactically well formed.
Syntax analyzing is also called Parsing and the phase called Parser.
The Parser
Has grammar use to check the
structure of tokens

5. Syntax in Programming
The analogy can be carried over to syntax of sentences in a programming language.
For example, an if-statement has the syntax.

6. Continue…
The parser ensures that sentences of a programming language that make up a
program abide by the syntax of the language. If there are errors, the parser will detect
them and reports them accordingly.

7. Grammar
A grammar is a powerful tool for describing and analyzing languages. It is a set of
rules by which valid sentences in a language are constructed. Here’s a trivial
example of English grammar
Subject, verb-phrases, adverb, verb, object
This is a university.
Computers run the world.
I never tell lies

8. Basics of CFG grammar
production a grammar rule that describes how to replace/exchange symbols.
nonterminal a grammar symbol that can be replaced/expanded to a sequence of
symbols.
terminal these are the symbols in a grammar that cannot be replaced by anything else.
start symbol a grammar has a single nonterminal (the start symbol) from which all
sentences derive.
derivation a sequence of applications of the rules of a grammar that produces a finished
string of terminals.

14. Most left and Right Derivation
If one statement can be derived by both left most derivative and right most derivative
from a given production rule called Ambiguous grammar.

15. Any Question