Problem: The axiom of foundation established that every set can be constructed from the bottom up in an ordered succession of steps by way of the principles of Zermelo and Fraenkel, in such a manner that if one set belongs to another then the first must necessarily come before the second in the succession, hence excluding the possibility of a set belonging to itself. To demonstrate that the addition of this new axiom to the others did not produce contradictions, von Neumann introduced a method of demonstration, called the method of inner models, which later became an essential instrument in set theory.
What excluded a set from belonging to itself in set theory?
The answer is the following: if one set belongs to another then the first must necessarily come before the second in the succession


The Districts of Germany (Kreise) are administrative districts, and every state except the city-states of Berlin, Hamburg, and Bremen consists of "rural districts" (Landkreise), District-free Towns/Cities (Kreisfreie Städte, in Baden-Württemberg also called "urban districts", or Stadtkreise), cities that are districts in their own right, or local associations of a special kind (Kommunalverbände besonderer Art), see below. The state Free Hanseatic City of Bremen consists of two urban districts, while Berlin and Hamburg are states and urban districts at the same time.
How many urban districts are in Bremen?
two


Input: Federal Bureau of Investigation
During the September 11, 2001 attacks on the World Trade Center, FBI agent Leonard W. Hatton Jr. was killed during the rescue effort while helping the rescue personnel evacuate the occupants of the South Tower and stayed when it collapsed. Within months after the attacks, FBI Director Robert Mueller, who had been sworn in a week before the attacks, called for a re-engineering of FBI structure and operations. He made countering every federal crime a top priority, including the prevention of terrorism, countering foreign intelligence operations, addressing cyber security threats, other high-tech crimes, protecting civil rights, combating public corruption, organized crime, white-collar crime, and major acts of violent crime.

What tower was Leonard W. Hatton Jr attempting to evacuate?
Output: South Tower


Input: Article: Genetic studies have found significant African female-mediated gene flow in Arab communities in the Arabian Peninsula and neighboring countries, with an average of 38% of maternal lineages in Yemen are of direct African descent, 16% in Oman-Qatar, and 10% in Saudi Arabia-United Arab Emirates.

Now answer this question: How many people in Oman-Qatar have African lineage?

Output: 16%


Article: A series of experiments performed from the late 1800s to the early 1900s revealed that diabetes is caused by the absence of a substance normally produced by the pancreas. In 1869, Oskar Minkowski and Joseph von Mering found that diabetes could be induced in dogs by surgical removal of the pancreas. In 1921, Canadian professor Frederick Banting and his student Charles Best repeated this study, and found that injections of pancreatic extract reversed the symptoms produced by pancreas removal. Soon, the extract was demonstrated to work in people, but development of insulin therapy as a routine medical procedure was delayed by difficulties in producing the material in sufficient quantity and with reproducible purity. The researchers sought assistance from industrial collaborators at Eli Lilly and Co. based on the company's experience with large scale purification of biological materials. Chemist George Walden of Eli Lilly and Company found that careful adjustment of the pH of the extract allowed a relatively pure grade of insulin to be produced. Under pressure from Toronto University and a potential patent challenge by academic scientists who had independently developed a similar purification method, an agreement was reached for non-exclusive production of insulin by multiple companies. Prior to the discovery and widespread availability of insulin therapy the life expectancy of diabetics was only a few months.

Question: Why was insulin therapy delayed?
Ans: difficulties in producing the material in sufficient quantity and with reproducible purity


Input: Qing dynasty
Losing the First Sino-Japanese War of 1894–1895 was a watershed. Japan, a country long regarded by the Chinese as little more than an upstart nation of pirates, annihilated the Qing government's modernized Beiyang Fleet, then deemed to be the strongest naval force in Asia. The Japanese victory occurred a mere three decades after the Meiji Restoration set a feudal Japan on course to emulate the Western nations in their economic and technological achievements. Finally, in December 1894, the Qing government took concrete steps to reform military institutions and to re-train selected units in westernized drills, tactics and weaponry. These units were collectively called the New Army. The most successful of these was the Beiyang Army under the overall supervision and control of a former Huai Army commander, General Yuan Shikai, who used his position to build networks of loyal officers and eventually become President of the Republic of China.

Who beat the Chinese in the First Sino-Japanese War?
Output:
Japan