<prompt> Yakha inguqulo eyinkimbinkimbi yalesi sigwebo Ukukhetha okuvamile ukuthi u-I abe ongapheli futhi u-U aqukethe wonke amaqoqo amancane ka-I.  <response>: Yiqiniso, inguqulo eyinkimbinkimbi yomusho ithi Inketho evamile iwukuba i-I ibe engapheli futhi i-U iqukathe wonke ama-cofinite subsets we-I, ngaphandle kwalokho i-ultrafilter iyinhloko, futhi i-ultraproduct i-isomorphic kwenye yezici. 