This is a tool for exploring Venn diagrams. The diagrams presented are randomly generated. You can change the first diagram (in the top left corner) by entering a Boolean expression using the three propositional letters R A G. The diagram to the left shows the state represented by each region.

Your Boolean expression must be written in Javascript notation. As well as the letters and the Boolean operators, || (OR), && (AND), and ! (NOT), you can use the constants true (TRUE) and false (FALSE). You can also use the conditional operator  condition ? expr1 : expr2  (IF THEN ELSE, or ITE), spaces, and parentheses ( ).

The text in the input box will turn red when you enter symbols other than those specified above. The Venn diagram will change whenever the text in the box constitutes a well-formed expression.

You can change the number of diagrams displayed. For example, the URL www.inf.ed.ac.uk/teaching/courses/inf1/cl/tools/venn/?n=2 will display a 2x2 array; n can be any integer in the range 1-16.