Finish Basement Bathroom

[Alpha Q]

I bought a new house and asked to have a bathroom roughed in the basement. It has an ejection pit. I am in the construction industry and can do the plumbing myself. I just don't understand how they ran the piping. I have enclosed photos and it was roughed in for a shower, not a tub. Any help would be greatly appreciated. The 001j pic is two pipes coming out of floor, the 2 pipes on the wall in the same pic seam to go to the vent pipe.

[Bob NH]

In the 005 picture there are two pipes from the ejection pit. The one without the valve is clearly a vent, based on the direction of the tees. The one with the valve appears to be the discharge.

I think you will find that the two pipes in picture 001 drain to the ejector pit. If you run some water into them, the pump should start to pump it out.