Shower drain and tee

[joe77]

I am currently in the process of placing a shower pan over a concrete slab. 2 in. PVC pipe is being used. A vanity is being placed nearby (approx. 3ft) from vent. I am considering placing a tee just below the shower drain (see pic) then the trap below that. Will this setup work? My only concern is that the trap will drain that far below the elbow before it reaches the main soil line.

[Plumber2000]

You can't do that, only place you can have such a setup is under a kitchen sink.