Indicating Semi-continuous Variables
Semi-continuous variables:
- Example: Minimum order quantities
- Either (2 <= x <=4) or (x = 0)
0 1 2 3 4
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- 2 * i <= x <= 4 * i, i e {0, 1}
- Check:
- 2 <= x <= 4 indicated by i=1
- 0 <= x <= 0 indicated by i=0
- Use to indicate x is “strictly positive”
- epsilon * i <= x <= 4 * i, i e {0, 1}
- where epsilon is small positive number, e.g. 0.00001.