(Or A0) A language for the UNIVAC I or II, using three-address code instructions for solving mathematical problems. A-0 was the first language for which a compiler was developed. It was produced by Grace Hopper's team at Remington Rand in 1952. Later internal versions were A-1, A-2, A-3, AT-3. AT-3 was released as MATH-MATIC.

["The A-2 Compiler System", Rem Rand, 1955].

[Sammet 1969, p. 12].