Discussion on: Superimposed or Built-up Beams

If I well understood, if we have two layers in the beam, having the same I and the same E, with a load P in the middle of the upper beam, then the upper beam will be loaded with P/2, and its reactios at the extremes will be P/4 and P/4, and the same will be for the lower layer?
The two layers are both iso-static?
Can we exclude that between the upper and the lower beam, neglecting frictions, there are reactions somehow distributed (which will be possible only if the upper layer is hyper-static)?
Thank you in advance for your reply.

Patrizio Tiberti