GradedModule ++ GradedModule -- a binary operator, usually used for direct sum

GradedModule ++ GradedModule -- a binary operator, usually used for direct sum

Synopsis:

Operator: ++ -- a binary operator, usually used for direct sum

Input:

an instance of class GradedModule.

Output:

an instance of class GradedModule.

Code:

     -- ../../../Macaulay2/m2/gradedmodules.m2:252-258
     GradedModule ++ GradedModule := GradedModule => (C,D) -> (
          E := new GradedModule;
          R := E.ring = C.ring;
          if R =!= D.ring then error "expected graded modules over the same ring";
          scan(union(spots C, spots D), i -> E#i = C_i ++ D_i);
          E.components = {C,D};
          E)