plus

 +   Plus.
    X + Y adds matrices X and Y. X and Y must have compatible sizes. In the
    simplest cases, they can be the same size or one can be a scalar. Two
    inputs have compatible sizes if, for every dimension, the dimension
    sizes of the inputs are either the same or one of them is 1.

    C = PLUS(A,B) is called for the syntax 'A + B' when A or B is an object.

    See <a href="matlab:helpview('matlab','MATLAB_OPS')">MATLAB Operators and Special Characters</a> for more details.

    Documentation for single/plus
       doc single/plus