Syntax diagram
A syntax diagram is used in theoretical computer science to graphically represent the syntax of a rule set. In particular, formal languages up to the class of context-free languages and thus also the syntax of programming languages can be represented in a syntax diagram due to the subset property.
Implementation of the EBNF in a syntax diagram
Each extended Backus-Naur-Form (EBNF) can be converted one-to-one into a syntax diagram using the graphic opposite.
example
The picture below shows the implementation of the definition of natural numbers from the EBNF in a syntax diagram.