Modeling question

> Hi,
>
> Can anybody help me to formulate this ? just not able to figure this out
>
> x is a continuous variable. Can take any positive value including 0.
> w is a 0/1 binary variable
>
> if x > 0, I want w = 0
> if x = 0, I want w = 1

This should work:

x ≤ (1-w)·M where M=x.up
x ≥ 0.001·(1-w)