Visa policy of the United States

The visa policy of the United States deals with the requirements which a foreign national wishing to enter the United States must meet to obtain a visa, which is a permit to travel to, enter and remain in the United States. Visitors to the United States must obtain a visa from one of the United States diplomatic missions unless they come from one of the visa exempt countries or Visa Waiver Program countries. The same rules apply to Puerto Rico and the United States Virgin Islands while slightly different rules apply to Guam, Northern Mariana Islands and American Samoa.

The United States gives a visitor visa exemption to:

A2

A2, A02, A002, A², A.II or A-2 may refer to:

Media

Military

List of County-Designated Highways in Michigan

The County-Designated Highways in Michigan comprise a 1,241.6-mile-long (1,998.2 km) system of primary county roads across the US state of Michigan. Unlike the State Trunkline Highway System, these highways have alphanumeric designations with letters that correspond to one of six lettered zones in the state. The CDH system was created in 1970 in response to the business concerns of a woman from Saugatuck. Her one-woman crusade in the 1960s started after the highway in front of her motel was turned over to local control as a county road and removed from state highway maps when the nearby freeway opened. After nearly a decade of efforts, the first two test highways were designated, one each in the Lower and Upper peninsulas of the state and included on the 1970 state highway map. The CDH system was created and expanded in scope c. October 5, 1970, after it was approved by the County Road Association of Michigan and the State Highway Commission.

A-0 System

The A-0 system (Arithmetic Language version 0), written by Grace Hopper in 1951 and 1952 for the UNIVAC I, was the first compiler ever developed for an electronic computer. The A-0 functioned more as a loader or linker than the modern notion of a compiler. A program was specified as a sequence of subroutines and arguments. The subroutines were identified by a numeric code and the arguments to the subroutines were written directly after each subroutine code. The A-0 system converted the specification into machine code that could be fed into the computer a second time to execute the said program.

The A-0 system was followed by the A-1, A-2, A-3 (released as ARITH-MATIC), AT-3 (released as MATH-MATIC) and B-0 (released as FLOW-MATIC).

The A-2 system was developed at the UNIVAC division of Remington Rand in 1953 and released to customers by the end of that year. Customers were provided the source code for A-2 and invited to send their improvements back to UNIVAC. Thus A-2 was an early, and perhaps the first, example of free and open-source software.