Negation in Rules - Gnorion/BizVR GitHub Wiki
We need to be able to handle expressions of the form:
not 'red' (meaning any value other than 'red')
not('red','green') (meaning any value other than 'red' and 'green')
other (meaning any value not covered by any other rule in the current ruleset (DT)
Effectively the not operator applied to a set of (boolean) expressions is equivalent to determining the gaps in those expressions.
If you don't want the expression to include the null value then its better to use the equivalent positive phrasing rather than not
| Expression | Equivalent to |
|---|---|
| not (<18) | >=18 or null |
| not (<18,>100) | [18..100] or null |
| not (<100,>100) | 100 or null |
| not (<100,>0) | null or F cannot be true for any value |
| not (<0,[25..50],>100) | [0..25),(50..100] or null |
For strings
| Expression | Equivalent to | Notes |
|---|---|---|
| not ('red') | <'red',>'red' | either before 'red' or after 'red' or null |
| not('red','green') | <'green',('green'..'red'],>'red' or null |