"Acta Mat Compos Sin" is not a specific word or term; it appears to be a combination of several different words or abbreviations. Therefore, it is not possible to provide synonyms for this phrase. It is important to remember that synonyms are words that have similar meanings to another word. However, without a clear understanding of the intended meaning or context of "Acta Mat Compos Sin", it is impossible to identify suitable synonyms. If you provide more information or clarify the intended meaning, I would be happy to assist you with synonym suggestions for specific words within that phrase.