pub(super) fn parse_multi_syllable_symex<'a: 'b, 'b, I>(
rule: SymexSyllableRule,
script_required: Script,
) -> Boxed<'a, 'b, I, String, Full<Rich<'a, Token>, State<'a>, ()>>where
I: Input<'a, Token = Token, Span = SimpleSpan> + ValueInput<'a>,