[grammar] → ([block] (/\n\.\n?/ [block])*)?

[block] → [pragma-block]
	→ [rule-block]
	→ [where-block]

[pragma-block] → [pragma] (/\n(?!\t)/ [pragma])*

[rule-block] → [rule-decl] [rule-case] (/\n\t/ [rule-case])*

[where-block] -> where /\n\t/ ([rule-block] /\n\t/)+ in /\n\t/ [rule-block]

[pragma] → pragma [pragma-name] [pragma-body]