Formal Language And Its Type.finite automata and formal languages
Formal Language And Its Type.finite automata and formal languages
Contents
- 1 🔍 What is a Formal Language?
- 2 🧾 Types of Formal Languages (Chomsky Hierarchy)
- 3 ⚙️ Finite Automata (FA)
- 4 📘 Applications of Formal Languages
- 5 📺 Want a Video in Hindi?
- 6 📥 Need PDF Notes or a Short Course?
- 6.1 Formal Language And Its Type.finite automata and formal languages
- 6.2 UNIT – I – Formal Language and Automata – SMT1404
- 6.3 An Introduction to Formal Languages and Automata
- 6.4 FORMAL LANGUAGES AND AUTOMATA THEORY
- 6.5 DIGITAL NOTES ON FORMAL LANGUAGES AND …
- 6.6 Formal Languages and Automata Theory
- 6.7 Formal Languages and Automata Theory.
📘 Formal Language and Its Types | Finite Automata and Formal Languages
Formal language and automata theory form the mathematical foundation of computer science, especially compiler design, language processing, and artificial intelligence.
🔍 What is a Formal Language?
A formal language is a set of strings made from a finite alphabet and governed by specific syntactic rules. It is used to define and analyze languages that computers can process.
- Alphabet (Σ): A finite set of symbols (e.g., Σ = {0,1})
- String: A finite sequence of symbols from an alphabet
- Language (L): A set of strings over an alphabet (L ⊆ Σ*)
🧾 Types of Formal Languages (Chomsky Hierarchy)
| Language Class | Automaton / Recognizer | Grammar Type | Example Language |
|---|---|---|---|
| 1️⃣ Regular Languages | Finite Automata (FA) | Type 3 – Regular | Binary numbers divisible by 3 |
| 2️⃣ Context-Free Languages | Pushdown Automata (PDA) | Type 2 – CFG | Balanced parentheses ((())) |
| 3️⃣ Context-Sensitive | Linear Bounded Automata (LBA) | Type 1 – CSG | a^n b^n c^n where n ≥ 1 |
| 4️⃣ Recursively Enumerable | Turing Machine (TM) | Type 0 – Unrestricted | All computable languages |
⚙️ Finite Automata (FA)
Used to recognize regular languages. There are two main types:
1. DFA (Deterministic Finite Automaton)
- One unique path for each input symbol
- No ε (epsilon) transitions
2. NFA (Non-Deterministic Finite Automaton)
- Multiple paths allowed for a single input
- Can include ε-transitions
Formal Definition of DFA:
DFA = (Q, Σ, δ, q0, F)
Q = set of states
Σ = input alphabet
δ = transition function (Q × Σ → Q)
q0 = initial state
F = set of accepting states
📘 Applications of Formal Languages
- Design of compilers and interpreters
- Lexical analysis using regular expressions
- Pattern matching, string searching (grep, regex)
- Natural language processing
- Design of protocols, algorithms, and AI models
📺 Want a Video in Hindi?
You can watch an explanation on YouTube:
🔗 Formal Language and Automata Theory in Hindi – Part 1
📥 Need PDF Notes or a Short Course?
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- Handwritten notes
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- GATE/NET/UGC-level MCQs
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