# plus sign

There are two main uses of the plus sign$+$” (which is a simplified form of “&”) in the mathematics and the applying sciences:

• The original use is as the sign for the binary operation of numbers and other elements of rings and algebras, vectors, etc.:

 $a\!+\!b\;:=\mbox{\, the sum of\, }a\mbox{\, and\, }b$
• There is also a special use for the unary operation identity mapping concerning numbers and other ring elements:

 $+a\;:=\;a\mbox{\; (for all }a)$
 Title plus sign Canonical name PlusSign Date of creation 2013-03-22 17:35:43 Last modified on 2013-03-22 17:35:43 Owner pahio (2872) Last modified by pahio (2872) Numerical id 5 Author pahio (2872) Entry type Definition Classification msc 00A06 Classification msc 00A05 Synonym plus Related topic Sum Related topic SumOfSeries Related topic SignumFunction Related topic OppositeNumber Related topic ProductOfNegativeNumbers