To insert a formula in a proof:
 - click on the button below
 - double-click in the white space
 - begin a mission with the menu "Example level X"
 - or click on one hypothesis you may use on the top of the screen

To move a tree:
 - you simply move them by drag and drop by moving the conclusion of a tree
 
To apply a rule:
 - click on a node and then click on a button on the left corresponing on the rule you want to apply
 - click on one node, then press Ctrl and click a second node by keeping Ctrl pressed. You can then apply a rule on two nodes
- click on a node to make possible hypothesis that is a subformula of it
- move some treeproofs on the same line and draw an horizontal line on the bottom of the trees
- you can also connect several proof trees together to a conclusion with the mouse by moving them