Key points:

• A patent claim is invalid for indefiniteness under § 112, ¶2 if the claim, read in light of the patent’s specification and prosecution history, fails to inform, with reasonable certainty, those skilled in the art about the scope of the invention.
• The Federal Circuit’s formulation–that a patent claim is not definite so long as the claim is “amenable to construction” and the claim, as construed, is not “insolubly ambiguous”–does not satisfy the definiteness requirement.