each and every element of the claim (i.e., anticipation) is pretty straight forward, rejections based on inherency are more tricky. Inherency refers to a determination of your patent examiner that even though an element is not explicitly taught by the prior art, it would necessarily be present in the teachings of the prior art.

A few common situations of inherency are the following.

(1) Prior art Product is identical:When a prior art reference teaches a structure which is identical to your claimed structure, any claimed properties or functions are presumed to be inherent. For example, if you claim a table and a prior art reference teaches your table, the fact that you add to your claim that your table is sturdy will be regarded by your patent examiner as inherently taught. A claim to something which is old does not become patentable upon the discovery of a new property.

(2) Inherency and Method Claims: If a prior art device, in its normal and usual operation would necessarily perform your claimed method, your examiner can also make a proper rejection based on the inherency. The method claimed will be considered to be anticipated by the prior art device under inherency. Moreover, if the prior art device is the same as a device described in your specification for carrying out your claimed method, it can be assumed the device will inherently perform your claimed method.

Real life examples are never as simple as the examples above.

Once an examiner presents reasoning to support the determination of inherency, the burden shifts to you (the applicant) to rebut such evidence.

Some possible strategies to rebut an inherency assertion by your patent examiner is to point out that inherency may not be established by probabilities or possibilities. The fact that a certain result or characteristic may occur or be present in the prior art is not sufficient to establish inherency of that result of characteristic.

You may also want to try to argue that what you are claiming is a new use for an old structure rather than simply a newly-recognized result or outcome of a structure. An amendment reciting specific claimed steps using the old structure may help in this argument.

For more information on Inherency see MPEP 2112.