Variable mathInlineRuleConst

Inline rule for parsing [[$ LaTeX $]] inline math.

Triggered by a BLOCK_OPEN ([[) token. Looks for a $ text token immediately after, collects the LaTeX source until the closing $]] sequence, and produces a math-inline element.

Fails if:

• No $ follows the [[
• A newline is encountered within the LaTeX source
• The closing $]] sequence is not found