If a dice was to be rolled twice, the tree diagram would look like this: There are four possible outcomes. To work out the probabilities of each total outcome, multiply the probabilities together.

If a dice was to be rolled twice, the tree diagram would look like this: There are four possible outcomes. To work out the probabilities of each total outcome, multiply the probabilities together.

Tree representations figure throughout Llull's work, culminating in Arbor scientiae, a collection of tree-based diagrams of science and human knowledge, published in 1296.