COMPILER DESIGN

Detailed explanation-1: -A they are unnecessary, in reality. B the symbols used have well-defined meaning. C only the form of the string of symbols is significant.

Detailed explanation-2: -Formal symbols are usually thought of as purely syntactic structures, composed into larger structures using a formal grammar, though sometimes they may be associated with an interpretation or model (a formal semantics).

Detailed explanation-3: -Formal language is less personal than informal language. It is used when writing for professional or academic purposes like graduate school assignments. Formal language does not use colloquialisms, contractions or first-person pronouns such as “I” or “We.” Informal language is more casual and spontaneous.

Detailed explanation-4: -Formal language is characterized by the use of standard English, more complex sentence structures, infrequent use of personal pronouns, and lack of colloquial or slang terms. Informal language allows the use of nonstandard English forms, colloquial vocabulary and typically shorter sentence structures.

Detailed explanation-5: -Symbol: A symbol is a user-defined entity. Alphabet: An alphabet is a finite set of symbols denoted by in automata. Alphabets are a set of symbols used to construct a language. Example, 0, 1 is binary alphabet, A…, Z, a… z is the alphabet set for the English language.