Litmus test (politics) Litmus test (politics) A litmus test is a question asked of a potential candidate for high office, the answer to which would determine whether the nominating official would proceed with the appointment or nomination. The expression is a metaphor based on the litmus test in chemistry, in which one is able to test the general acidity of a substance, but not its exact pH. Those who must approve a nominee, such as a justice of the Supreme Court of the United States, may also be said to apply a litmus test to determine whether the nominee will receive their vote.
Machine-or-transformation test generally insufficient to make an otherwise ineligible method claim patent-eligible. The PTO Guidance Memo explains that "[t]his means the machine or transformation must impose meaningful limits on the method claim's scope [for it] to pass the test." What makes a limitation meaningful is unstated, but perhaps that concept can be defined in terms of whether the limitation places only an insubstantial limitation on claim scope or preemptiveness. The second corollary is that insignificant extra-solution activity will not transform a patent ineligible principle into a patentable process. The PTO Guidance Memo explains that "[t]his means reciting a specific machine or a