Hi,

I am not sure wether I am in the right forum for this question and it may even turn out banal.

I think to remember that the often cited, unmovable truth 1+1=2 is not so absolute as it seems to be. Could someone explain me, if there are mathematical systems or preconditions under which 1+1=2 is false or not entirely true anymore and how this works in simple terms?

Thank you very much for your patience with a math idiot.

Cheers.