[lemma=□] □
[lemma=system] □
In particular , most auction systems force buyers and sellers to trust the auctioneer ; alternative secure systems are inflexible and have a high computational and / or communication overhead . Canada and Britain 's healthcare systems have flaws and may be inferior to other national systems , but they are clearly superior to what we have in America , both in terms of cost and in terms of coverage . In Fuller 's terms " Systems are aggregates of four or more critically contiguous relevant events ... Year 2000 problems embedded in those systems put investors ' ability to conduct transactions at risk . In addition , many CAM systems have characteristics commonly found in mainstream health care , such as a focus on good nutrition and preventive practices .