Are compositional (mereological) relations always distinct from definitional relations, or can compositional relations be considered definitional relation in some cases? Does this depend on whether we are considering nominal definitions or real definitions?
A compositional relation R1 could be "water is composed of H2 and O". A definitional relation R2 could be "water is defined as H2 and O". Could one say that R1 is just a kind of definitional relation, perhaps a real definition? What makes me hesitant to assert this, is that i think of definitions as somewhat arbitrary ideas, while compositional relations seem to be true or false with respect to reality. Also definitions seem to be symmetric relations while compositional relations are necessarily anti symmetric. Maybe this is just a semantic issue with no material implications...
My understanding is that there is some kind of taxonomy of relations, involving causal relations, compositional relations, real definitions, nominal definitions, etc. Essentially my question is about where compositional relations and definitional relations fit in this taxonomy, if composition is a subtype of definition. Any references to not to difficult texts would be appreciated (i am not a philosopher).
Many thanks in advance!