MM? Using roman numerals... Seriously, I do value good notation, but for this particular case, juxtaposition, we do use it for multiplication - in algebra, wher

MM? Using roman numerals... Seriously, I do value good notation, but for this particular case, juxtaposition, we do use it for multiplication - in algebra, where it's easy to find the boundary of a number, and variables are always 1 symbol long, so 'xyz' is a product of three values, not a name of one. Coming back - notation is important, but sometimes it's hard to find "the best" or even "good enough". Newton's primes as symbols of differentiation used alongside with Leibniz' dy/dx, and there is the shortcut for "differentiated by time" as dot on top of the function symbol, so for various cases different notation is more convenient.