Tub piping @ slab foundation

The tub appeared to have no trap or visible vent. Being this is a slab foundation how would they attach the trap. It is required on a slab home or am I to be corrected.

Besides the stand pipe for the washing machine being improprly installed & the cold water not operating my concern was the trap & vent. The tub did drain properly.

Thanks

Dave

84106 Streetsboro 039 (Small).jpg

David, the trap is typically below the slab.