:::: Clearer to whom exactly? ">" is in linguistics is what "+" and "-" are in mathematics, the very basic notational apparatus. We shouldn't be redefining notation that has been in consistent use for 2 centuries. ">" is a well-defined operator meaning "lexeme on the left side, either reconstructed or attested, yields by regular sound changes lexeme on the right side". Arrows can mean all kinds of things, esp. in mathematical logic and some programming languages..