I read the rules incorrectly. It appears that "0xfor" is a valid way to represent the two tokens "0xf" and "or". The rule, which I initially misinterpreted, is

I read the rules incorrectly. It appears that "0xfor" is a valid way to represent the two tokens "0xf" and "or". The rule, which I initially misinterpreted, is: > Whitespace is needed between two tokens only if their concatenation could otherwise be interpreted as a different token (e.g., ab is one token, but a b is two tokens). Since "0xfor" cannot be interpreted as a different (single) token, whitespace is not needed. (I'm not a fan of this particular consequence of that rule, and I suspect it was not intended, but it says what it says.)