A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime minister is the presiding member and chairman of the cabinet. In a minority of systems, notably in semi-presidential systems of government, a prime minister is the official who is appointed to manage the civil service and execute the directives of the head of state.

In parliamentary systems fashioned after the Westminster system, the prime minister is the presiding and actual head of the government and head of the executive branch. In such systems, the head of state or the head of state's official representative (i.e. the monarch, president, or governor-general) usually holds a largely ceremonial position, although often with reserve powers.

The prime minister is often, but not always, a member of parliament and is expected with other ministers to ensure the passage of bills through the legislature. In some monarchies the monarch may also exercise executive powers (known as the royal prerogative) which are constitutionally vested in the crown and may be exercised without the approval of parliament.

Alexis Tsipras (Greek: Αλέξης Τσίπρας) (born 28 July 1974) is a Greek left-wing politician, member of the Hellenic Parliament, president of the Synaspismós political party and head of the Coalition of the Radical Left (SYRIZA) parliamentary group.

On 8 May 2012, Karolos Papoulias, the President of Greece, mandated him to form a coalition government. One day before, Antonis Samaras (ND) had given up his attempt to form a coalition. Each politician mandated in this way in Greece are allowed 72 hours for such an attempt. In the evening of 9 May 2012, Tsipras announced he had failed to form a coalition government.

Tsipras was born July 28, 1974, in Athens. He studied civil engineering at the National Technical University of Athens (NTUA). After graduating in 2000, he pursued graduate training in land surveying and planning at an inter-departmental programme of NTUA, and he worked as a civil engineer in the construction industry. He undertook several projects and wrote several studies related to the city of Athens.

Greek may refer to anything related to:

Greek may also refer to:

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example, 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2 and 3 in addition to 1 and 6. The fundamental theorem of arithmetic establishes the central role of primes in number theory: any integer greater than 1 can be expressed as a product of primes that is unique up to ordering. This theorem requires excluding 1 as a prime.

The property of being prime is called primality. A simple but slow method of verifying the primality of a given number n is known as trial division. It consists of testing whether n is a multiple of any integer between 2 and √n. Algorithms that are much more efficient than trial division have been devised to test the primality of large numbers. Particularly fast methods are available for primes of special forms, such as Mersenne primes. As of 2011^[update], the largest known prime number has nearly 13 million decimal digits.

Minister can mean several things:

Alexis (Ancient Greek: Ἄλεξις, c.394 BC – c.288 BC) was a Greek comic poet of the Middle Comedy period. He was born at Thurii (in present day Calabria, Italy) in Magna Graecia and taken early to Athens, where he became a citizen, being enrolled in the deme Oion (Οἶον) and the tribe Leontides. It is thought he lived to the age of 106 and died on the stage while being crowned. According to the Suda, a 10th century encyclopedia, Alexis was the paternal uncle of the dramatist Menander and wrote 245 comedies, of which only fragments now survive, including some 130 preserved titles.

It was said he had a son, called Stephanus, who also wrote comedies. He appears to have been rather addicted to the pleasures of the table, according to Athenaeus.

He won his first Lenaean victory in the 350s BC, most likely, where he was sixth after Eubulus, and fourth after Antiphanes. While being a Middle Comic poet, Alexis was contemporary with several leading figures of New Comedy, such as Philippides, Philemon, Diphilus, and even Menander. There is also some evidence that, during his old age, he wrote plays in the style of New Comedy.