Building Formulae

Goal

The challenge formula is displayed inside the small black panel. The goal is to build the same formula inside the big black panel. Initially the big black panel contains only the atomic elements of the challenge formula. In order to compose them and get the whole formula, six actions are proposed:
  1. Copy: Clicking on a formula copies it
  2. Dissolve: Clicking on a formula removes its top operator. If the formula is atomic, it cancels it.
  3. And: Clicking on a first formula f1 and dragging towards another formula f2 creates the formula f1 ∧ f2.
  4. Or: Clicking on a first formula f1 and dragging towards another formula f2 creates the formula f1 ∨ f2.
  5. Imp: Clicking on a first formula f1 and dragging towards another formula f2 creates the formula f1 -> f2.
  6. Neg Clicking on a formula f adds a negation on top: ¬f.
Hints:
This applet has been tested with Java 1.4.2 (Sun). Check your version of java
Laurent Théry