Mealey's (December 18, 2015, 1:33 PM EST) -- WASHINGTON, D.C. — An August 2015 ruling by the Federal Circuit U.S. Court of Appeals that relied upon the “change of law” exception to invalidate two patents as indefinite will stand, thanks to a denial Dec. 17 of a combined petition for rehearing and rehearing en banc (Dow Chemical Company v. NOVA Chemicals Corp., et al., Nos. 14-1431, -1462, Fed. Cir.; 2015 U.S. App. LEXIS 21924)....