Problem: Extract the answer to the question from the following context. Question: How often do the Three Jewels change? Context: Traditionally, the first step in most Buddhist schools requires taking refuge in the Three Jewels (Sanskrit: tri-ratna, Pāli: ti-ratana)[web 19] as the foundation of one's religious practice. The practice of taking refuge on behalf of young or even unborn children is mentioned in the Majjhima Nikaya, recognized by most scholars as an early text (cf. Infant baptism). Tibetan Buddhism sometimes adds a fourth refuge, in the lama. In Mahayana, the person who chooses the bodhisattva path makes a vow or pledge, considered the ultimate expression of compassion. In Mahayana, too, the Three Jewels are perceived as possessed of an eternal and unchanging essence and as having an irreversible effect: "The Three Jewels have the quality of excellence. Just as real jewels never change their faculty and goodness, whether praised or reviled, so are the Three Jewels (Refuges), because they have an eternal and immutable essence. These Three Jewels bring a fruition that is changeless, for once one has reached Buddhahood, there is no possibility of falling back to suffering.

A: never


Problem: Extract the answer to the question from the following context. Question: Who might be interested in the definition of a vacuum? Context: Vacuum is space void of matter. The word stems from the Latin adjective vacuus for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is lower than atmospheric pressure. The Latin term in vacuo is used to describe an object as being in what would otherwise be a vacuum.

A: Physicists


Problem: Extract the answer to the question from the following context. Question: Which approach is less inclusive? Context: The second approach to the problem took as its base the notion of class, and defines a set as a class which belongs to other classes, while a proper class is defined as a class which does not belong to other classes. Under the Zermelo–Fraenkel approach, the axioms impede the construction of a set of all sets which do not belong to themselves. In contrast, under the von Neumann approach, the class of all sets which do not belong to themselves can be constructed, but it is a proper class and not a set.

A: Zermelo–Fraenkel approach


Problem: Extract the answer to the question from the following context. Question: Which was the more specialized engine? Context: Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer. Considered the "father of the computer", he conceptualized and invented the first mechanical computer in the early 19th century. After working on his revolutionary difference engine, designed to aid in navigational calculations, in 1833 he realized that a much more general design, an Analytical Engine, was possible. The input of programs and data was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. The Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.

A:
difference