I believe EqPoint allows you to pass around a bag of functions (aka an interface, which Zig does not have as a concept) to functions which can be written in terms of "I need these functions" rather than in terms of a concrete type.
For the same reason things like "a, c as equal points" or even "some and other as equal points". That could just as easily be automatically parsed. Just a matter of sticking conventions, as if scriptural terseness was of any utility in the kind of case, apart maybe for esoteric representation that will filter non initiated people.