What is the "doctrine of equivalents" in patent law?

The doctrine of equivalents is a fundamental concept in patent law that allows a court to hold a party liable for patent infringement even when the infringing product or process does not fall within the literal wording of the patent claims. This doctrine is critical in ensuring that patent protection remains effective against variations or modifications of a patented invention that are not explicitly covered by the claims but perform the same function in substantially the same way to achieve the same result.

By permitting a broader interpretation of patent claims, the doctrine of equivalents helps to prevent competitors from circumventing patent protection through minor alterations of a patented invention. It emphasizes the intention behind the patent, ensuring that the underlying invention and its objectives are safeguarded, even against slight variations.

The other options do not accurately capture the essence of the doctrine of equivalents, as they focus on different aspects of patent law that do not relate directly to the interpretation of claims or the principles of infringement.