Context Free Grammars Automata Theory by ComputeNow - August 23, 2018August 23, 20180 Context free grammars (CFGs) are used to describe context-free languages. A context-free grammar is a set of recursive rules used to generate patterns of strings. A context-free grammar can describe all regular languages and more, but they cannot describe all possible languages. Context-free grammars are studied in fields of theoretical computer science, compiler design, and linguistics. CFG’s are
Definition of Pushdown Automata Automata Theory by ComputeNow - August 17, 20180 Definition of Pushdown Automata Pushdown Automata is a finite automata with extra memory called stack which helps Pushdown automata to recognize Context Free Languages. A Pushdown Automata (PDA) can be defined as : Q is the set of states ∑ is the set of input symbols Γ is the set of pushdown symbols
Equivalence of Automata Automata Theory by ComputeNow - August 15, 20180 Equivalence of Automata Two automata A and B are said to be equivalent if both accept exactly the same set of input strings. Formally, if two automata A and B are equivalent then if there is a path from the start state of A to a final state of A labeled
Deterministic Finite Automata (DFA) Automata Theory by ComputeNow - August 13, 20180 Definition of Deterministic Finite Automata Deterministic Finite Automata (DFA) consists of 5 tuples {Q, ∑, q, F, δ}. Q : set of all states. ∑ : set of input symbols. ( Symbols which machine takes as input ) q : Initial state. ( Starting state of a machine ) F : set of final
Definition of Finite Automata Automata Theory by ComputeNow - August 8, 2018August 12, 20180 Definition of Finite Automata: A finite automata (FA) is a simple idealized machine used to recognize patterns within input taken from some character set (or alphabet) C. The job of an FA is to accept or reject an input depending on whether the pattern defined by the FA occurs in the input. A finite automaton consists
