This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
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Question: Passage: Even though some proofs of complexity-theoretic theorems regularly assume some concrete choice of input encoding, one tries to keep the discussion abstract enough to be independent of the choice of encoding. This can be achieved by ensuring that different representations can be transformed into each other efficiently.

Answer: What can not be achieved by ensuring different representations can transformed into each other efficiently?


Question: Passage: In July 1977, General Zia-ul-Haq overthrew Prime Minister Zulfiqar Ali Bhutto's regime in Pakistan. Ali Bhutto, a leftist in democratic competition with Islamists, had announced banning alcohol and nightclubs within six months, shortly before he was overthrown. Zia-ul-Haq was much more committed to Islamism, and "Islamization" or implementation of Islamic law, became a cornerstone of his eleven-year military dictatorship and Islamism became his "official state ideology". Zia ul Haq was an admirer of Mawdudi and Mawdudi's party Jamaat-e-Islami became the "regime's ideological and political arm". In Pakistan this Islamization from above was "probably" more complete "than under any other regime except those in Iran and Sudan," but Zia-ul-Haq was also criticized by many Islamists for imposing "symbols" rather than substance, and using Islamization to legitimize his means of seizing power. Unlike neighboring Iran, Zia-ul-Haq's policies were intended to "avoid revolutionary excess", and not to strain relations with his American and Persian Gulf state allies. Zia-ul-Haq was killed in 1988 but Islamization remains an important element in Pakistani society.

Answer: When was the regime in Pakistan accepted by General Zia-ul-Haq?


Question: Passage: On 20 February 2001, the bureau announced that a special agent, Robert Hanssen (born 1944) had been arrested for spying for the Soviet Union and then Russia from 1979 to 2001. He is serving 15 consecutive life sentences without the possibility of parole at ADX Florence, a federal supermax prison near Florence, Colorado. Hanssen was arrested on February 18, 2001 at Foxstone Park near his home in Vienna, Virginia, and was charged with selling US secrets to the USSR and subsequently Russia for more than US$1.4 million in cash and diamonds over a 22-year period. On July 6, 2001, he pleaded guilty to 15 counts of espionage in the United States District Court for the Eastern District of Virginia. His spying activities have been described by the US Department of Justice's Commission for the Review of FBI Security Programs as "possibly the worst intelligence disaster in U.S. history".

Answer:
Who had spied for the Soviet Union before 1979?