Decomposition.md

@@ -53,5 +53,8 @@ Every sub-domain has an extended part called ghost
 
 [[uploads/Domain_decomposition_external.jpg]]
 
-With the dashed red box we indicate the local domain while with the othe color boxes we indicate the external Ghost boxes that cover this extended part, these boxes are indicated by G5_0 G8_0 G9_0 and G9_1
+With the dashed red box we indicate the local domain while with the othe color boxes we indicate the external Ghost boxes that cover this extended part, these boxes are indicated by G5_0 G8_0 G9_0 and G9_1.
+These boxes can be calculated as the intersection of the extended domain with the adjacent sub-domains.
+Note also that each external ghost box of a sub-domain is an internal ghost box on another processor sub-domain
 
+[[uploads/Domain_decomposition_internal.jpg]]