
Suppose a set X={xα>0|α∈I} is an uncountable set. We will show that the sum of all elements of X is infinite. Consider the family of the following sets. Sn:={xα∈X∣xα≥1n} Then ⋃n∈NSn=X X is uncountable, so there exists n0∈N such that Sn0 is an infin..
mathe
2025. 1. 13. 13:38