(Copyright) A test for determining whether substantial similarity exists between two works in an action for copyright infringement. The court first applies an abstraction test where it dissects the copyrighted work's structure and isolates each level of abstraction. This is called the abstraction test. The court then examines each level of abstraction and separates out ideas, processes, facts, public-domain information, and merger material which cannot be protected. This is called the filtration test. In the comparison test, the court compares protectable expression with the accused work to determine if there has been substantial misappropriation. See Computer Associates Int'l, Inc. v. Altai, Inc., 982 F.2d 693 (2d Cir. 1992).