The commonest way in which we bridge between informal and formal notation is by defining translations from diagrammatic notations to logic. In Section 2.1 we use a box and arrow diagram as an interface for a system of binary relations. In Section 2.3.1 we use an operator diagram to give us the first stage in refinement of our formal operator definitions. Similarly, in Section 2.3.2 we use a diagrammatic representation of functions applied to data as a means of obtaining the beginnings of our decision procedure definitions. In Section 4.1 we compare two different entity description diagrams by translating each into logic. Section 4.2 describes a more abstract form of diagrammatic language, built purely with the aim of translating to set expressions and thence to FOPC. The structure of the shutdown logic used in Section 5.3 is described using a diagram similar to that used in some types of electronic circuit design. In Section 7.1 we use the diagrammatic conventions of system dynamics modelling and translate these to the logical expressions for our formal model, prior to describing some of the sources of uncertainty which it contains.