Au/Ra Au/Ra Jamie Lou Stenzel (born 15 May 2002), known by her stage name as Au/Ra, is a pop singer-songwriter, who collaborated with CamelPhat in the 2018 single "Panic Room", and was featured in Norwegian DJ Alan Walker's number-one single "Darkside" in the same year. Au/Ra was born in Ibiza, but was since raised in St. John's, Antigua by a musical family—her father being the German producer Torsten Stenzel. Her stage name Au/Ra consists of two elements from the periodic table: Au stands for gold, a transition metal with the atomic number 79, while Ra stands for radium, an alkaline earth
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