The tree editor is where a branch is decomposed. Suppose the branch is A⊃B then when the editor opens it will appear as:
| A⊃B | |||
| Left Branch | Same Branch | Right Branch | |
| A | |||
| ~A | |||
| B | |||
| ~B |
Now you select which components in the left most column are used to decompose the proposition and then you insert them in the proper branches. To insert a component, select its row and branch column by clicking on it. Or, use the cursor arrow keys to highlight the proper cell and then press the space bar.
| A⊃~B | |||
| Left Branch | Same Branch | Right Branch | |
| A | |||
| ~A | ~A | ||
| B | B | ||
| ~B |
To return to the tree so that the decomposition can be inserted into the tree, click on Ok or press <Enter>.
Click here for a detailed discussion of Exercise T1, Part I, Number 1.