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03-60-214: regular expression and automata

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Try RegexTester

• Running at course web site as an applet;– http://cs.uwindsor.ca/~jlu/214/regex_tester.htm

• Write regular expressions and try the match(), find() methods;

• Try the string 3314 instead of 3.14

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Try FSM simulator

• Run the simulator – The java code can be downloaded at

• http://cs.uwindsor.ca/~jlu/214/fsm.zip

– Unzip the zip file • >unzip fsm.zip

– Go to the directory fsmsim_bgm/classes– Run the java program: >java FSM

• Define the FSM in the text file;– The text files are in fsm-sources

• Generate the transition diagram;– Machine/new machine

• Run the simulator and observe how strings are recognized.

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• select “save target as”

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Construct and run a dfa from a text file

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NFA //Type(a|b)*abb Fig 3. 23 in dragon booka b // input alphabetq0 q1 q2 q3 // Machine statesq0 // the initial stateq3 // final stateq0 b q0 // transitions: input state, input

symbol, output stateq3 b q0q1 a q1q2 a q1q3 a q1q0 a q1 q1 b q2 q2 b q3end

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Construct a dfa in GUI

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JFLAP: RENFADFAm. DFA

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