Editing Prior art (section)

==Usage in litigation==
Arguments claiming prior art are used in defending and attacking patent validity. In one U.S. case on the issue, the court said:

{{Quote|One attacking the validity of a patent must present clear and convincing evidence establishing facts that lead to the legal conclusion of invalidity. 35 U.S.C. § 282. To establish invalidity under 35 U.S.C. § 103, certain factual predicates are required before the legal conclusion of obviousness or nonobviousness can be reached. The underlying factual determinations to be made are

* (1) the scope and content of the prior art; 
* (2) the differences between the claimed invention and the prior art; 
* (3) the level of ordinary skill in the art; and 
* (4) objective evidence of non-obviousness, such as commercial success, long-felt but unsolved need, failure of others, copying, and unexpected results.
|[[Graham v. John Deere Co.]], 383 U.S. 1, 17, 148 USPQ 459, 467 (1966).<ref name="grahamSupCt">[https://scholar.google.com/scholar_case?case=9105652591497305710 Graham v. John Deere Co. of Kansas City] {{Webarchive|url=https://web.archive.org/web/20170424052550/http://scholar.google.com/scholar_case?case=9105652591497305710 |date=2017-04-24 }}, 383 US 1, Sup. Ct., 1966.</ref><ref name="tokai">[https://scholar.google.com/scholar_case?case=16458331733551319754 Tokai Corp. v. Easton Enterprises], Inc., 632 F. 3d 1358 at 1363-64, Ct. App. (Fed. Cir.), 2011.</ref>
}}