Plus
(Built-in Mathematica Symbol) x + y + z represents a sum of terms.
SubPlus
(Built-in Mathematica Symbol) SubPlus[expr] displays as expr_+.
CirclePlus[x, y, ...] displays as x\[CirclePlus]y\[CirclePlus]....
PlusMinus[x] displays as \[PlusMinus]x.PlusMinus[x, y, ...] displays as x \[PlusMinus] y \[PlusMinus] ....
Unicode: 2295. Alias: Esc c+ Esc. Infix operator. x ⊕ y is by default interpreted as CirclePlus[x,y]. Used in mathematics for various operations related to addition, such as ...
Unicode: F39E. Alias: Esc + Esc. Infix operator with built-in evaluation rules. Used in entering mixed fractions. x Esc + Esc y is interpreted as x+y, but Esc + Esc has ...
Unicode: 2213. Alias: Esc -+ Esc. Prefix or infix operator. ∓ x is by default interpreted as MinusPlus[x]. x ∓ y is by default interpreted as MinusPlus[x,y].
Unicode: 00B1. Alias: Esc +- Esc. Prefix or infix operator. ± x is by default interpreted as PlusMinus[x]. x ± y is by default interpreted as PlusMinus[x,y].
Unicode: 002B. Raw operator. Equivalent to the ordinary ASCII character with code 43.
Unicode: 228E. Infix operator. x ⊎ y is by default interpreted as UnionPlus[x,y]. Used to denote union of multisets, in which multiplicities of elements are added.