challenging proof

[powloka]

Prove, that a set Af of points, where exists lim_t→x+ f(t), but f is not continuous function in x, is a countable set.

 

Thank you, I dont know, how to prove it.

[mathematic]

Try to clarify. What are A and X? What is Af?

[imatfaal]

!

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So poloka could you show where you have got to and what has stopped your progress - hopefully members can then help you to overcome your difficulties yourself.