trig X on if trig Y off

[XORadmin]

If not I will develop it.

Hi,
I supposed the subject is pretty self explanatory.
If not I will develop it.
I would love to do it using the Triggers 16 but can't find a way even through the mapping matrix.
Any idea ? 

Actually I will do it now
My goal is to generate complex sequences using a pool of samples.
Random triggers, random samples, never the same sequence but wihtout the overlapping.
Typically I'd love to set a probability on trigger X and trigger Y triggered depending on the status of X.
I hope to be clear enough.

I do understand. But a status of X except for if it is a local signal or feed somehow into the NerdSEQ is not available. Not developable in a responsible way either.