One of the sentences in this paragraph is very unclear and is leading to confusion as to what the standard for the written description and in particular possession actually is. Quoting from MPEP 2161.01 I paragraph 6 the sentence in question is the first sentence from the following two sentences:
Specifically, if one skilled in the art would know how to program the disclosed computer to perform the necessary steps described in the specification to achieve the claimed function and the inventor was in possession of that knowledge, the written description requirement would be satisfied. Id. If the specification does not provide a disclosure of the computer and algorithm in sufficient detail to demonstrate to one of ordinary skill in the art that the inventor possessed the invention including how to program the disclosed computer to perform the claimed function, a rejection under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, for lack of written description must be made"
Decisions such as Finisar, Blackboard, Noah and Williamson build upon each other in establishing that simply because a person skilled in the art could devise a way to achieve a function is not evidence that an algorithm is present in the disclosure or that the inventor was in possession of the knowledge. These cases (particularly Noah) go through the process for determining whether an algorithm is present. The problem with the sentence I have brought out is that it appears to mix the test for enablement (whether one skilled in the art would know how to program the disclosed computer) with possession (the inventor was in possession of that knowledge) and rather than clearly showing what constitutes the possession test it instead brings the skills of the person of ordinary skill into the conversation which again is a test of enablement. The other sentences in 2161.01 I that pertain to the person of ordinary skill all relate to whether the person of ordinary skill can reasonably conclude the inventor possessed the invention, not whether they would know how to program the disclosed computer. So this particular recitation seems to negate everything else that was stated in the other portions of 2161.01 section I as to how to establish whether possession exists in a computer implemented claim by clearly showing the algorithm that the inventor had in the written disclosure which must be more than simply stating function.