- I see — “sign relation” is a special term for triadic relations of some kind (with some properties); like this: thing in first position and thing in second position must refer to the thing in third position. Where “refer” is an unary partial function from one thing to another. Am I on a right direction?
It is not uncommon in practice to find a sign having many interpretant signs and many referent objects Generally speaking, then, we start out with a sign relation as a subset of a cartesian product where are sets called the object domain, sign domain, interpretant sign domain, respectively. A definition of a sign relation — there are a few canonical ones we find useful in practice — will specify what sort of constraint is involved in forming that subset.