After reading the Logic Pro X manual and combining various environment modules in different combinations, I must admit that I'm struggling at realizing the following simple task:
I'd like to build an octave transpose switch that is controlled by MIDI notes played on an external USB MIDI keyboard.
Hitting the lowest note (C2) and the highest note (C5) simultaneously should transpose the MIDI input by one octave up, and hitting C2+B4 should transpose it by 1 octave down.

I can detect the appropriate single notes using transformer objects, but how would I detect a combination of two keys? I cannot find a simple "Logical AND" module or anything similar.

Thanks for any ideas *yes*