Another interesting one, similar to the previous one but only a little different. This time I want to be more quantitative.
The same question of the input voltage momentarily being -11V, far beyond the maximum rating -0.5V, also exist, if from the perspective of the U24D gate (TC4071BP). This may well be 'clamped' down to safe voltage by the internal protection diodes. But even if this is the case, to me this is the internal business of the gate but does not change the fact that its input has been exposed to an unsafe input voltage (according to the datasheet). We can park this one (because it has been discussed, and I might be too pedantic here.)
This circuit, as far as I see, works this way. The output (RHS) remains L (i.e. active H), but rises to H whenever any of the inputs (LHS) rises to H. Dur to the existence of the R/C, any rising of the three highlighted inputs will be extended from its rising edge with a constant duration (determined by RC, which is given, the L/H threshold of the gate, and probably its propagation delay).
That is, any of these three input signals, whenever it comes and however short the pulse might be, will have at least the duration of this extension on the output side. [1]
To me this is meaningful only when the width of any of these three signals may be narrower than this extension. Because otherwise this extension will only be 'buried' (as overlap) in the input pulse.
Before figuring this out, here comes a question first about the input threshold voltage. According to the datasheet, say for Vdd 9V, these two voltages thresholds , which are different (highlighted as 5.5V and 4.5V, respectively). This looks like to me that there will be a voltage range where the logic state of the input is not determined. This will inevitably happen when the input is fed with the voltage that complies with the exponential curve of an RC charging/discharging circuit. What's going to happen when the input voltage is between 4.5V and 5.5V?
[Edit]
[1] With another look, this now does not seem to be correct.