# abs

The`abs`

filter is a numeric filter whose value is the absolute value of its single numeric argument:
abs -4 == 4 abs power a - power AIf its argument does not match the current position, neither does the

`abs`

filter.
# Examples

The`abs`

filter is used in platzwechselecho.cql and platzwechseln2.cql to check that the knights which have
interchanged positions have ranks and files that are at least 3 apart:
abs (rank N1 - rank N2)>= 3 abs (file N1 - file N2)>= 3