The image of Example 1. The cursor" <--CLICK " only appears when CLICK is owed on the red sentence. It happens according to the Rigid Sequence of operations to perform for getting the resolution of the problem. It Is not able to otherwise do. After having selected the First Operation " Fill" this result is gotten:

Now I must Decant the content in the container of left

As the problem asks me a total of 8 and I have now only a value of 4, I must give me another value of 4. To get this I Fill the Container of Right

Now the problem is resolved
contact me