Browsable ISO EBNF Grammar

Grammar extracted by Vadim Zaytsev, see the Grammar Zoo entry for details: §wip/metasyntax/ebnf-iso-2/extracted
Source used for this grammar: ISO/IEC 14977:1996(E), Information Technology—Syntactic Metalanguage—Extended BNF, 1996, §8.2 “Extended BNF used to define itself informally”, page 10 [PDF]

Summary

• Total 18 production rules with 28 top alternatives and 123 symbols.
• Vocabulary: 38 = 21 nonterminals + 17 terminals + 0 labels + 0 markers.
• Total 21 nonterminal symbols: 18 defined (syntax, syntax_rule, definitions_list, single_definition, term, exception, factor, primary, empty, optional_sequence, repeated_sequence, grouped_sequence, terminal_string, meta_identifier, integer, special_sequence, comment, comment_symbol), 0 root (—), 1 top (syntax), 3 bottom (decimal_digit ², letter ², character ⁴).
• Total 17 terminal symbols: 0 keywords (—), 0 letters (—), 0 numerics (—), 17 signs ("=", ";", "|", ",", "-", "*", "[", "]", "{", "}", "(", ")", "’" ², """ ², "?" ², "(*", "*)").

Syntax

syntax ::=
	syntax_rule+

syntax_rule ::=
	meta_identifier "=" definitions_list ";"

definitions_list ::=
	single_definition ("|" single_definition)*

single_definition ::=
	term ("," term)*

term ::=
	factor ("-" exception)?

exception ::=
	factor

factor ::=
	(integer "*")? primary

primary ::=
	optional_sequence
	repeated_sequence
	special_sequence
	grouped_sequence
	meta_identifier
	terminal_string
	empty

empty ::=
	ε

optional_sequence ::=
	"[" definitions_list "]"

repeated_sequence ::=
	"{" definitions_list "}"

grouped_sequence ::=
	"(" definitions_list ")"

terminal_string ::=
	"’" character+ "’"
	""" character+ """

meta_identifier ::=
	letter (letter | decimal_digit)*

integer ::=
	decimal_digit+

special_sequence ::=
	"?" character* "?"

comment ::=
	"(*" comment_symbol* "*)"

comment_symbol ::=
	comment
	terminal_string
	special_sequence
	character

Maintained by Dr. Vadim Zaytsev a.k.a. @grammarware. Last updated in September 2015. [↑]