Assuming Reals, then including Assumptions → x1 > 0 && x2 > 0
in this Limit
would seem to be necessary in order for f
to have defined values for any n
.
Even with this amendment though, the result is not as expected (i.e., Max[x1, x2]
, or something equivalent, because by symmetry, if the limit is x2
when x1 < x2
, then the limit is x1
when x2 < x1
).
Since this isn't happening, I think you've found a gap in Limit
's coverage.