Plus

• Plus has attributes Flat, Orderless and OneIdentity.

• The default value for arguments of Plus, as used in x_. patterns, is 0.

• Plus[ ] is taken to be 0.

• Plus[x] is x.

• x + 0 evaluates to x, but x + 0.0 is left unchanged.

• Unlike other functions, Plus applies built-in rules before user-defined ones. As a result, it is not possible to make definitions such as 2+2=5.

• See Section 1.1.1.

• See also: Minus, Subtract, AddTo, Increment, Total.

• New in Version 1; modified in 3.