I am aware that when we have a linear problem subject to OR constraints, the LP would be a non-convex optimisation problem. For example,

${x = 0}$ OR ${1<=x<=2}$.

I could not find much explanation on the internet concerning a detailed explanation of this situation. I’d appreciate if anyone could explain this in more detail.

Similar questions in other sites:

https://math.stackexchange.com/questions/4158912/infinite-number-of-or-constraints-in-linear-programming

https://stackoverflow.com/questions/50987517/expressing-an-or-constraint-in-linear-programming