Mathematics — Real Analysis · double-sequence-iterated-limits
Problem
Suppose the joint limit of {xn,m}n,m=1∞ is L, and suppose that for all n, limm→∞xn,m exists, and for all m, limn→∞xn,m exists. Then show limn→∞limm→∞xn,m=limm→∞limn→∞xn,m=L.