id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ejpam-749	Xie, Tao; Zuo, Kezheng	Fredholmness of Combinations of Two Idempotents	2010	8	.pdf	application/pdf	2847	180	81	Therefore the idea of generalize the invertibility of aP + bQ − cPQ or aP + bQ − cQP to the invertibility of aP + bQ − cPQ − dQP or more generally aP + bQ− cPQ− dQP − ePQP − f QPQ− · · · can not be achieved. Finally, we also have ind(aP + bQ− cPQ) = ind(I − P31D∗1(I −Q11)	cache/ejpam-749.pdf	txt/ejpam-749.txt