The 77Ws do many different flights.
From YVR:
NRT (Flight starts in YYZ), HKG, LHR (starting in the spring).
From YUL:
CDG, FRA and LHR
From YYZ:
2 x LHR, GRU, FRA
This should be fairly accurate, but it is only of the top of my head - a few of them may have switched come the winter.
Also its common to see YVR-YYZ on 77Ws or 77Ls (mostly for AC1 and AC33 plus return)