What does "possible to define" mean in general?
First I thought it means that "can not lead to a contradiction", but such seems to be hard to prove.
Then for the proof I was looking at, involving natural numbers, it turned out to mean "exists at least one number for which definition holds for each case", which is was relatively easy to prove.
Does "possible to define" always mean "exists something satisfying for all cases"?
My native language is not english. Is that might be the reason that I found this non-obvious?