As discussed in past posts, the Broadest Reasonable Interpretation (BRI) standard applied by the USPTO in examining patent applications is often stretched well past what is reasonable. A recent case before the Federal Circuit (in re LF Centennial) illustrates one of the classic arguments advanced by Examiners. Namely, that because a claim term has a feature in common with the prior art, it is reasonable to conclude that the broadest reasonable interpretation of that claim terms includes the prior art.   

The case involved a US 8,079,311, disclosing a TV support structure, and in particular the claim term referring to a "spine."  Claim 1 set forth, among other limitations: 

a first short spine having a height which extends from a floor to said upper shelf support, said first short spine forming a structural component of said console assembly when said first short spine is secured to a said upper and lower shelf supports of said console assembly;
a second long spine, having a height which extends from a floor to said upper surface of said upper shelf and further extends above said upper surface of said supper shelf terminating in an upper end which provides an elevated support for a flat panel television, said second long spine forming a structural component of said console assembly when said second long spine is secured to said console assembly; ...

Figure 1 of the patent shows the spine 22, which are distinguished from the side panels 48 and 50.

The PTAB upheld a rejection of claims based on a construction of "spine" as not requiring that the support element be centrally positioned, and thus found that side panels in the prior art satisfied the claim limitation at issue. The Patentee, first cited the dictionary definition of "spine" and then further argued that "spine" had a meaning that precluded side panels particularly because the patent specification distinguished the spine from the side panels. The USPTO argued that the PTAB's interpretation was reasonable because the specification defined the spine as extending from the floor to the upper shelf, and a side panel did the same. 

The Federal Circuit correctly recognized the logical errors in this line of reasoning. Simply because side panels may meet part of the requirements of a spine does not overcome the fact that they are lacking other basic elements of the definition of a spine. From the court: 

[The USPTO's] suggestion is fallacious: it employs a version of the fallacy of the undistributed middle, under which the two statements, “a dog is a four-legged pet” and “a cat is a four-legged pet,” are asserted to give rise to the inference that a dog is a cat. A common characteristic of a spine and a side panel does not allow a conclusion that one can be the other.

Fortunately the Federal Circuit still reviews the Board’s determination of the broadest reasonable interpretation of claim language de novo, at least where, as here, it is not based on any outside-the-patent understandings of technical language or other facts. In re Varma, 816 F.3d 1352, 1359 (Fed. Cir. 2016).