plus

Plus operation for ctau object.


Syntax
   f = plus(obj1, obj2)

Description
    plus(obj1, obj2) returns the coefficient sum obj1 + obj2.

Inputs
   obj1 = parcel1 (ctau object).
   obj2 = parcel2 (ctau object).

Output
   f    = obj1.coef + obj2.coef (ctau object)