id	keyword
ejpam-6834	set
ejpam-6834	nonempty
ejpam-6834	˜pdf
ejpam-6834	sets
ejpam-6834	pcf
ejpam-6834	level
ejpam-6834	fujita
ejpam-6834	define
ejpam-6834	pure
ejpam-6834	math
ejpam-6834	eur
ejpam-6834	appl
ejpam-6834	f.smarandache
ejpam-6834	proof
ejpam-6834	theorem
ejpam-6834	f−1