Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?
Until that topmost PNP turns on, nothing happens in the other 5 transistors, as far as I can tell from the schematic.

Its a hard-to-read drawing.

I've done similar circuits (high speed input clamps) on photodiode amplifiers for IRDA







simulate this circuit &ndash; Schematic created using CircuitLab