7.3.3 Realvec arithmetic

Realvecs may be set (=), added, subracted, and the like.

     // realvec foo created, filled with data, etc.
     ...
     
     realvec bar;
     bar = foo;
     // bar is now the same size and contains the same data
     
     // arithmetic
     baz = foo + bar;
     baz = foo + 3;