I'm reviewing for a final exam on Monday, and I have a question I was unable to answer on a previous test. The professor's notes were horrendous, and I can't find anything better online. They all seem to talk way over my head.
For each of the following pairs of literals, determine whether or not they are unifiable. If they do, show the unifiers.
- P(a), Q(g(x))
- P(x), Q(g(a))
I have a feeling that it's insanely easy, as the prof (despite teaching horribly, gives easy enough questions) but I still have no idea what to do.
There is no unification in either case, since whatever you substitute for $x$ (and perhaps $a$; you didn't state which symbols are variables to be substituted), the first expression of the pair will have $P$ as its outermost symbol and the second one will have $Q$.