triangular and square wave generator
The right hand op-amp looks like a comparator (with an open collector output). The emitter I suspect is pin 1 and this is tied to -15 V. Open collector outputs require a pull-up resistor hence the need for R5 in your circuit.

If you could link where you found this circuit this could be confirmed. I think the comparator matches the pin out of the LM311: -



Collector = pin 7 and emitter = pin 1.