There is no statutory requirement that formal logic be adhered to during examination of patent claims. Examiners and patent practitioners are free to use a wide variety of discussion and argument styles and topics, and these tend to be specific to the subject matter at hand and more informal than reliance on pure, formal logic. Yet there are times when a formal logic fallacy is committed in the rejection of a claim, and formal logic tools can be applied to the specifics to analyze and then formulate a response to refute the rejection. The following (fictionalized) example is given in generalized specifics, and followed by a formal logic discussion.

Suppose the independent claim under examination has, as an intended point of novelty, claim limitations involving moving an object (if this is a physical machine) or some specific data (if this is a processor-based invention) to a specified location responsive to a condition that the object or the data has some specified property, and leaving the object or the data where it was if the object or the data does not have the specified property. The Examiner, in an Office action rejecting the claims, has set forth a first reference that shows two possible locations for an object or data, and moving the object or data from the one location to the other. The Examiner has set forth a second reference that shows various conditions and properties the object or the data could have, and various operations that could be performed on the object or the data responsive to the object or data either having or not having the various conditions and properties. The Office action asserts that the claim limitations of “leaving the object or data where it was, and moving the object or data from where it was to the new location” are shown in the first reference, and the claim limitations of “responsive to the object or data having or not having the various conditions and properties” are shown in the second reference, therefore all of the limitations are shown in the combination of the references. Can you spot the logical fallacy in this argument?

In terms of formal logic, there is a logical fallacy in the proposition set forth in the rejection of the claims. The proposition is of the form of showing A in a first reference, and “responsive to condition B” in a second reference, with that assertion that this proves “A is responsive to condition B”. But, neither reference teaches a logical connection between A and B. The second reference teaches actions, in the second reference, that are responsive to condition B. The first reference teaches action A, possibly responsive to conditions taught in the first reference. But, the conditions in the first reference are not equivalent to the conditions in the second reference, and the actions taught in the first reference are not equivalent to the actions taught in the second reference. The two teachings cannot be logically combined to prove that A is responsive to condition B. That this is a logical fallacy can be shown by reductio ad absurdum, a formal logic proof style. Suppose that the proposition that A shown in the first reference, and “responsive to condition B” shown in the second reference, does show that A is responsive to condition B, is true. But, while the second reference teaches that action C is responsive to condition B, the second reference also teaches that action D is responsive to not condition B, which could be called action D is responsive to condition E. By the logical proposition, the combination of the first reference and the second reference therefore teaches that A is responsive to condition E, which is equivalent to A is responsive to not condition B. But, this contradicts the supposition that the combination of the references teaches that A is responsive to condition B. The two are in logical contradiction, which now disproves the proposition, by reduction to a contradiction or reductio ad absurdum.

In terms of arguments to be made during examination of patent claims, there is no teaching to combine the references. That the second reference teaches some other actions responsive to the condition that the object or the data has or doesn’t have some specified property has no bearing on whether or not the actions of leaving the object or data where it was, or moving the object or data from where it was to a new location as taught in the first reference are to be performed responsive to the conditions in the second reference. They are independent of one another, and neither reference teaches the connection between the actions in the first reference and the conditions in the second reference. Therefore there is no teaching to combine. Any Office-cited general-purpose motivation, such as that the two references are in the same or related fields, are general in nature, and do not direct or reveal that purported specific connection between the actions in the first reference and the conditions in the second reference. A proper combination of the two references would teach that the actions of the first reference are performed responsive to the conditions in the first reference, and the actions in the second reference, unrelated to those in the first, are performed responsive to the conditions in the second reference, unrelated to the conditions in the first reference. Only if one or both references teach a connection between actions in the first reference and conditions in the second reference would they be properly combined to show the claim limitations.

Returning to formal logic, the logical deduction from the proof by contradiction or reductio ad absurdum is that the combination of reference one and reference two shows that the actions A shown in the first reference are not dependent on the conditions B shown in the second reference, since the (fallacious) logical proposition could be used to show that action A is responsive to both B and not B. In other words, condition B is a “don’t care” condition for action A. Formal logic shows that the two references do not establish a connection between action A and condition B (or not B). In formal logic terms, according to the (fallacious) logical proposition and what is shown in the two references, A is dependent upon (B or not B), which logically resolves to just A (independent of or not dependent on any state of condition B).

Thus, the formal logic proves the invalidity of the proposition in the Office action, and the validity of arguing that the references do not teach or establish any connection between the actions of the first reference and the conditions in the second reference. Practically speaking, where formal logic is a useful tool is when it is not immediately clear how to argue against a claim rejection that somehow feels fallacious or just plain wrong. Formal logic can point to a logical fallacy advanced in the rejection, which can then point to what specific claim terms and what specific factual findings to apply and arguments to refute the rejection. For the patent practitioner, abstracting the rejection to formal logic terms clears away the specific details of the subject matter, and lets us look at whether or not the argument proposition or format itself, advanced in the rejection, is based on sound reasoning. If the argument itself is employing fallacious logic, the patent practitioner can then resolve this to the specific details of the subject matter, and develop a response strategy with reference to those details. While formal logical will not necessarily develop every possible response or argument (see, e.g., the incompleteness proof by Goedel), it can be used as good guidance and is a useful tool to have in the toolkit. The above examples are just one application of one part of formal logic, and there are many more constructs in formal logic and many more places where it can be applicable in reasoning during patent claim examination. This is all part of the art of patenting.