max
Themax filter takes two or more numeric or string arguments enclosed in parentheses. It returns the maximum of the arguments:
x=max(#Q #R #B)
y=max("pin" "mate")
y ≡ "pin"
The max filter matches a position if at least one of its arguments match the position.
Examples
Themax filter is used in queenpawnpinecho.cql. The filters there:
L=lca(source target)
max(distance(source L)
distance(target L))>= 4
is used to make sure that either the position named source or the position named target are a distance of at least 4 from their latest common ancestor.