Because of those classificatory interdependences, the three trichotomies intersect to form ten (rather than 27) classes of signs. There are also various kinds of meaningful combination. Signs can be attached to one another. A photograph is an index with a meaningfully attached icon. Arguments are composed of dicisigns, and dicisigns are composed of rhemes. In order to be embodied, legisigns (types) need sinsigns (tokens) as their individual replicas or instances. A symbol depends as a sign on how it "will" be interpreted, regardless of resemblance or factual connection to its object; but the symbol's individual embodiment is an index to your experience of the object. A symbol is instanced by a specialized indexical sinsign. A symbol such as a sentence in a language prescribes qualities of appearance for its instances, and is itself a replica of a symbol such as a proposition apart from expression in a particular language. Peirce covered both semantic and syntactical issues in his theoretical grammar, as he sometimes called it. He regarded formal semiotic, as logic, as furthermore encompassing study of arguments (hypothetical, deductive, and inductive) and inquiry's methods including pragmatism; and as allied to but distinct from logic's pure mathematics.