We describe some of the files from the JFLAP book that are all available off the JFLAP web site.
The language is a string of 2 or more a's followed by 0 or more b's such that the number of a's is divisible by 2 or 3, and the number of b's is divisible by 2 or 3.
Strings in the language include: aaaabbb, aaaaaabbbb, aaa
To run the NFA, first load the file into JFLAP. Then select "Input", then "Step with Closure". Enter a sample string such as aaaabbb. Then select "Step" repeatedly. This NFA is nondeterministic. After 2 steps, there are four possible configurations. The string is accepted when a final state is reached and all of the symbols in the string have been processed (the configuration turns green).
Load the file. To parse the grammar, select "Input", then "Brute Force Parse". Enter an input string, aaaaaaa, and click on "Start", then "Step" repeatedly. The parse tree is derived. To see the derivation, click on "Start" again, then "Noninverted Tree" and select "Derivation Table". Then "Step" repeatedly.
The language is a string of 1 or more a's followed by a string of b's with more b's than a's.
Load the file. Run similar to the NFA above, or try the multiple run by selecting "Input", then "Multiple Run". Enter in several input strings and then click on "Run Inputs" to see which are accepted.
Language is a string of 0 or more a's, followed by the same number of b's, followed by the same number of c's. Example strings accepted are: abc, aabbcc, aaabbbccc.
To run, load file, then select "Input", then "Render System". In the top right corner of the window there is a 0 and two arrows. Click the up arrow repeatedly to see the tree grow.