2.5.12. Negation

If constraint C π‘’π‘›π‘‘π‘Ÿπ‘¦ holds then constraint C π‘Žπ‘™π‘ π‘œ does not hold. Reciprocally, if constraint C π‘Žπ‘™π‘ π‘œ holds then constraint C π‘’π‘›π‘‘π‘Ÿπ‘¦ does not hold. Note that constraints C π‘’π‘›π‘‘π‘Ÿπ‘¦ and C π‘Žπ‘™π‘ π‘œ must also have exactly the same parameters, but not necessarily the same parameters restrictions.

EXAMPLE: As an example, the constraint C π‘Žπ‘™π‘ π‘œ = πš—πš˜πš_πšŠπš•πš•_πšŽπššπšžπšŠπš• (i.e.,Β prevent all variables to be assigned the same value) is the negation of constraint C π‘’π‘›π‘‘π‘Ÿπ‘¦ = πšŠπš•πš•_πšŽπššπšžπšŠπš• (i.e.,Β enforce all variables to be assigned the same value).