Obtaining required threshold levels & Output of Comparator built Schmitt Trigger

How can I set the required lower & upper thresholds in the circuit below?
What is the formula that determines these thresholds?
What is the range of output voltage obtainable using this circuit?
How the circuit actually works?

The circuit is on the following link.

**broken link removed**

Note: The circuit is voltage window detector circuit

there is no Dana, only Zul!

or in your case there is no formula, only dividers... the voltage at the input is the trip point...

At the trip point Vin+ = Vin-. Everything else is simple algebra (two equations in two unknowns, describing the voltage dividers)

Have you read the replies to the other threads you've created?

It's not a Schmitt trigger, a Schmitt trigger has hysteresis which that window comparator doesn't have.