, c n in parse p = with anchor a is carried out in such a way that constant c i is replaced by a grammatical role/function that is defined relative to a.
p1: "Ann gave Bill a hug" is rendered into the sequence "Ann V O1 D O2" because gave, Bill, a and hug bear the roles of verb (V), direct object (O1), determiner (D) for O2, and indirect object (O2) relative to Ann.