A single-supply, inverting Schmitt trigger was detailed in a previous Idea For Design (“Comparator Features Symmetrical Thresholds,” by Samuel Kerem, Electronic Design, March 6, p. 124).

This positive feedback – typical of Schmitt trigger behaviour – ensures rapid, clean switching of the digital output signal. Buffers IC3A and IC3B are necessary (particularly at high frequencies) to ...

The inverting schmitt trigger mode produces opposite polarity output. This is fed back to the non-inverting input which is of same polarity as that of output. This ensures positive feedback.

Assuming you want a Schmitt trigger in a circuit, you have plenty of options. There are ICs like the 74HC14 that include six (inverting) Schmitt triggers. On a schematic, ...