Hysteresis Comparator Calculation

NOTE: Use the minus sign "-" for negative voltages.
Positive Supply Voltage: (V)
Negative Supply Voltage: (V)
Results:
Vth (High Threshold Voltage):
(V)
R2/R1(Ratio resistor): 
Vtl (Low Threshold Voltage):
(V)
Vr (Reference voltage): 
(V)