Chemical element meaning "no life") for "nitrogen". For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry (IUPAC), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting "gold" rather than "aurum" as the name for the 79th element (Au). IUPAC prefers the British spellings "aluminium" and "caesium" over the U.S. spellings "aluminum" and "cesium", and the U.S.
Non-logical symbol over the signature mentioned above is the ordered group of integers. Its domain is the set formula_1 = {…, –2, –1, 0, 1, 2, …} of integers. The binary function symbol + is interpreted by addition, the constant symbol 0 by the additive identity, and the binary relation symbol < by the relation less than. Outside a mathematical context, it is often more appropriate to work with more informal interpretations. Rudolf Carnap introduced a terminology distinguishing between logical and non-logical symbols (which he called "descriptive signs") of a formal system under a certain type of interpretation, defined by what they