PDE in the first year!!! You're almost into metatheorems. Thats like... the end of the universe in PL. Props! Heck, I'm excited for you... thats very advanced. For me, PL took a year after SD (which was a year in itself!!!. Admittedly, my general acquaintance in predicate systems goes up to PD and a little bit of PD+. So I'll get back to this when I look over the PDE section in my book later today.
Also, did you go through truth trees in predicate logic? For some reason, they always avoided teaching that at school.