"structure of a language" is a pretty vague claim. Arguably one could conclude that Roman Numerals have the structure of a language too, but I wouldn't conclud

"structure of a language" is a pretty vague claim. Arguably one could conclude that Roman Numerals have the structure of a language too, but I wouldn't conclude from such a claim that roman numerals encode spoken language in durable form. Rather they are communicative in function, but through an illustrative rather than spoken frame of reference (Roman Numerals illustrate positions on a tally stick).