Entrenched in the woods fire by light mortar: TEM?

[Larry]

Light mortar attacks a unit in the woods entrenched. What is the TEM on the IFT roll: -1, +1, +2, +3 or +4?

 

[ds]

B13.3 gives an exact example of this:

A Mortar fires on a woods hex containing a squad in a foxhole. The Final TEM is +1 (+2 [foxhole] -1 [Air Burst] = +1).