OK guys, the deadline is up and I couldn't figure it out using your hints :(
Really appreciate the efforts though and I will format my question better next time as per the forum rules.
I have a homework question that asks me to draw up a truth table for the attached circuit.
As you can see I did this (I think correctly). There is also an attached question asking what function the circuit serves - I am not sure what function this is
Any pointers appreciated.