The Rationale and Specification of the ELLA Graphics System Version 1

The ELLA Graphical Language include graphical representations of most of the high level abstractions in text ELLA, in particular high level data-types and behavioural constructs. The Graphical Editor allows a designer to draw a circuit using these abstractions, which is then compiled into the ELLA system. Graphical text declarations can be used in exactly equivalent ways in the extended ELLA system specified here. Graphical input system thus gives the designer the freedom to use ELLA graphics or text where each is most appropriate, without losing the high level design capabilities when he prefers to use graphics. Keywords Great Britain Military publications Periodicals.