Sorry, why do you care if it's decidable? This is a mathematical system, not a computational one. If we required it to be computational, it couldn't give us results about computation.
It's just not a question one would normally ask, because we're trying to get a small theory of big objects, not the converse.
But then again, in this case, there's no possible issue. Since f, g and h are uniquely determined—none of those points has any internal structure—the diagram necessarily commutes. 'General function' or not, there is only one function from 1 to 2, and there is only one function from 2 to 3.
no subject
It's just not a question one would normally ask, because we're trying to get a small theory of big objects, not the converse.
But then again, in this case, there's no possible issue. Since f, g and h are uniquely determined—none of those points has any internal structure—the diagram necessarily commutes. 'General function' or not, there is only one function from 1 to 2, and there is only one function from 2 to 3.