Yes it is well defined...
'Is it so'' he started ' sir then show me a group which can give me an idea about the word 'well-defined' before i see its definition.' I really surprised about his question, but that is what any Mathematics teacher really expect from the student.
THE STUDENTS are really crazy about what they expect from a teacher. I am the wittness for many examples how they try to know the things. When I faced it for the first time, it is really an odd experience to me, I really thought that they are trying to teese the teachers with unnessesary things. Yes, it might be true in my space, if that day I did not face the twins in the other class.
The class is really quit when spell the word welldefined, then immidiatly the unexpected one stood and with great anxity "is it so"' he started "sir then show me a group which can give me an idea about the word 'welldefined' before i see its definition." I really surprised about his question, but that is what any Mathematics teacher really expect from the student.
They can never seen seperatly and, it is really too hard to identifie the individuals in the twins. When I was taking ateendence I observed, their names even the same but their roll numbers are different. Yes, the collection of students in the class are welldefined. Since what ever the situation even the case of twins i am able to identifi the inviduals, and can be univesally aceepted that belong to the group.
The same day in the office room I am wittness to a discussion among my collegueabout two students and their capability of getting result. And no one is compramising in with another's words. It taught me that the intellgent student of a class is not a well-defined collection.
I was really surprised to see the things there after,with the same look, and I really after that even now. let me continue the things, its really fun to know that the collection of boys in the class and collection girls in the class are disjoint , and the collection who play cricket and who play volleyball is adjoint.
The topic sets is really a fun game to us at that time we (i with my students)really enjoyed alot .....since we came to know what life does mathematics have ...