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Hi, Today let me post on the expected question kinds from Automata in NET exam. Expected Questions on Automata: 1. Questions related to grammar types    Say: type 2 grammar is called what? – CFG  2. Questions like true or false on certain statements on theories   Say: (i) Union of 2 regular sets is regular. (ii) Intersection of 2 regular sets is regular – Both (i) and (ii) are true. 3. Questions on regular expressions   Say: Two regular expressions will be given with an equal symbol (LHS = RHS). We have to either select the equivalent form or guess whether it is true or false, or pick out the right / wrong pair. Give a string and find out its regular expression. 4. Questions on Grammar   Say: Give a set of strings and find the grammar or give grammar and find its equivalent. Give derivations and find grammar. Something of this sort has been repeated in 2012 June and December. 5. Questions in Match form   Say:...

Hi, This is a continuation of the previous post on automata. 1. Basic Terms: 1. String – valid sequence of inputs / sequence of characters from £ 2. Language – pattern of strings accepted by automata / set of all strings accepted by automata 3. £ - Transition – without reading any input, moves from one state to another state 4. Regular expression - Representation of language 5. / - either or (a/b = a or b) 6.   . –   one element followed by another (a.b = ab) 7. + - Positive closure (one or more occurrences) 8. * - Kleen Closure (zero or more occurrences) 9. Regular expression is used in Lexical analysis phase of compiler 10. Homomorphism – substitution of strings for symbols 2. Finite Automata:   Finite Automata has no remembering capacity. It can be divided into: (1) Deterministic Finite Automata – DFA    (2) Non Deterministic Finite Automata – NFA NFA DFA Single input -> Multiple states ...

Greetings, Updating this blog after a very long time.. Let’s see something useful in terms of preparation of UGC-NET exam Let me start with the most boring (of most people) – Automata. But it’s in fact the easiest and the most interesting one if we understand the simple logic. Say, 1024 x 2 = 2048 is a big calculation if we memorize 2 - multiplication table. But if we know the logic of multiplying every digit by 2 and taking carry on to next integer, then this multiplication can be done in no time. Hierarchy of Automata: Type Grammar Language Automata Type 0 Unrestricted Recursively enumerable Language Turing Machines Type 1 Context sensitive Context Sensitive Language Linear Bounded Automata Type 2 Context Free Context Free Language Push Down Automata Type 3 Regular Regular Language Finite Automata Properties of Gr...