[Trigger] Limits

[Nichita_00]

How can I do something like, player has this: (Building A, B and C, Upgrades X, Y)

The player has a building A that can upgrade to building B.
The building be can research X and Y, but I want only X OR Y , and once
he researches one of them it gets replaced by building C.
Also, once he researches X or Y , he can't build building A (and B) anymore. How can I do this? I'm struggling for like a week, all attempts didn't work.
Can someone do a sample map? I REALLY need this, as it's a staple feature for my map.

 

[Storyyeller]

You could make it require a dummy unit, and then remove it when he does the research.

 

[madqc]

I did this. i hope that its what you need.

 

[Nichita_00]

Thank you. Your help shall be repayed.

 

[madqc]

allright no problem