| = EBNF | |
| https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form[EBNF^] (Extended Backus-Naur Form) syntax expresses a context-free grammar that formally describes a language. | |
| EBNF extends its precursor BNF (Backus-Naur Form) with additional operators allowed in expansions. | |
| Syntax (railroad) diagrams graphically depict EBNF grammars. |