This question is related to an answer I gave here:
So, please look at a simple worksheet containing only a few lines; the resuts are in the # comments.
### prinlevel stuff
And now the questions.
1. Why the first evalf(frac(Pi^20)) does not call `evalf/frac`?
(the second does, trace(`evalf/frac`) shows this if inserted).
Note that `evalf/frac`(Pi^20) returns 0.
2. Why evalf(frac(Pi^20)) depends on printlevel?
Note that if printlevel is changed to 20 (say) the result is again 23.
3. Why if we set interface(typesetting=standard) in a fresh session
the results are both 23?