It’s one of something. When one of something and one of another thing are observed it’s expressed as 1 and 1 so two rivers become one they represent a quantity of observation.

Then as 1 and 1 totaling two rivers they come together then exist as 1.

Representation is relative on an arbitrary border of quantity. The rules leak for any rule that exists.

One father and one mother have a kid. One and one make another one totaling three.

• and • make •.

Usually a person will substitute 1 for the observation of a “thing” so • will be father, and another • mother +1+1=+1

One unit and another one unit makes a third unit. Yet one unit plus another unit is two units.