An example of an inverting comparator with hysteresis using the LM319.
The trip levels, REF_HI and REF_LO, are set at +/-1V but due to the x2 input attenuation, wWith respect to the input signal, the upper and lower trip levels are at +/-2V.
A spreadsheet for the calculation of REF_HI and REF_LO for given resistor and supply values is attached.
AN4071: Introduction to comparators, their parameters and basic applications
Section 4.2 External hysteresis.