import numpy
import awkward as ak
import vector


def compound_selections(events, options, debug):

    # dphi(MET, tau1)
    tauVector = vector.awk({"pt": events['tau1_pt'], "eta": events['tau1_eta'], "phi": events['tau1_phi']})
    METVector = vector.awk({"pt": events["MET_pt"], "phi": events["MET_phi"]})

    events["dphi_MET_tau1"] = tauVector.deltaphi(METVector)


    # Write helicity variables stuff right here if needed

    return events
