>if you use that logic, yes.
That's the way functions work. If (for example) f(x) = 3x + cos x, then for any argument, you replace all occurences of "x" with that argument. So, f(15) would be 3(15) + cos 15, and f(abc) would be 3abc + cos abc.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
