Let  be a
field,
and let
 be a
field,
and let
-    
be an
inhomogeneous linear system
over  , and let
, and let
-    
be the corresponding homogeneous linear system. If  is a solution of the inhomogeneous system and if
 is a solution of the inhomogeneous system and if  is a solution of the homogeneous system,
 is a solution of the homogeneous system, 
 then 

 is a solution of the inhomogeneous system.