------o
| &quot;B&quot;           | &quot;B&quot;           |
| &quot;B&quot;           | &quot;u&quot;           |
o---------------o---------------o

JD: And the symmetrical for L(B).

This looks wrong, at least, if you meant to form the 2-adic
projection of L(A) on the subspace !O!x!S!, which one would
commonly write as &quot;Proj_OS(L(A))&quot; or as &quot;L(A)_OS&quot; for short,
and the 2-adic projection of L(A) on the subspace !S!x!I!,
which is written &quot;Proj_SI(L(A))&quot; or &quot;L(A)_SI&quot; 