The problem where it messes up precedence if you already use parentheses, so that you need to add more parentheses to the substitutions, reminds me of the probl

The problem where it messes up precedence if you already use parentheses, so that you need to add more parentheses to the substitutions, reminds me of the problem with one common explanation of CSS specificity. Simplifying the model a bit, specificity is a tuple of (id, class, tag), so that `#foo #bar` is (2, 0, 0) and greater than `#foo .baz` which is (1, 1, 0). Well, some tried saying “treat it as a number”, leading to 200 and 110, and you can clearly see which number is bigger. The trouble with that approach is the numerical base: no number of classes will outweigh an ID, so (1, 11, 0) is not greater than (2, 0, 0), but if you want to represent it as a three-digit number, well, you’re stuck. Just like you can here add more parentheses to the substitution to keep it working, you could increase the numeric base; e.g. at this point hexadecimal would still work, 0x1b0 < 0x200. Not sure exactly what to call this category of limitation, but you see it in diverse places where people have designed things without considering the upper limits of what they can cope with.