Complexity of comparison unary>binary
The problem is in coNLOGTIME, for example using the following algorithm. As is well known, one can determine the length of input $n$ in binary in DLOGTIME. Then, read off at most $\log n$ bits from the end of the input to find $j$ (if it is longer, reject). This also determines $i=n-1-\lfloor\log(j+1)\rfloor$ (I am assuming one character for the separator), so it remains to check that $i&gt;j$, and that the beginning of the input is indeed a valid unary encoding: only the last part uses nondeterminism. (That is, the problem would be in DLOGTIME if it were defined so that any string of length $i$ counted as a unary encoding of $i$.)