Assume Tom conceives of a new [[mousetrap]] on January 1, 2006. Tom works diligently from January 1, 2006, to February 1, 2006, to prepare a patent application, and Tom files his patent application on February 1, 2006. Thus, Tom actuallyconstructively reduced his invention to practice on February 1, 2006. Assume Jerry conceives of the same mousetrap on January 10, 2006, and diligently files a patent application on the new mousetrap on January 20, 2006. Under the first-to-invent system, Tom is entitled to the patent on the mousetrap, because he conceived the mousetrap before Jerry and still worked diligently to actually reduce it to practice by filing. Actual and constructive reduction to practice should be distinguished. Filing a diligently prepared application constitutes constructive reduction to practice only and can be antedated by evidence of an actual reduction to practice.<ref>[http://www.uspto.gov/web/offices/pac/mpep/documents/0700_715_07.htm#sect715.07 715.07 Facts and Documentary Evidence [R-3] - 700 Examination of Applications<!-- Bot generated title -->]</ref> If both Tom and Jerry claimed the same invention, the USPTO would institute an interference proceeding between Tom and Jerry to review evidence of conception, reduction to practice and diligence.
As a further extension of the example, assume Tweety conceived of the same mousetrap on December 31, 1990. Tweety never told anyone about the mousetrap and did not work on reducing the mousetrap to practice for many years due to financial reasons. Tweety finally actually reduced the mousetrap to practice on February 15, 2006. Because Tweety did not diligently work to reduce the invention to practice in the period before others' conception of the same invention, he is not entitled to a patent over Tom or Jerry.<ref>[http://www.uspto.gov/web/offices/pac/mpep/documents/0700_715_07_a.htm#sect715.07a 715.07(a) Diligence - 700 Examination of Applications<!-- Bot generated title -->]</ref>
