I believe GP wanted to say that Symbolic Execution is a subset of Abstract Interpretation; because here the prolog expert is wrong: SE is not strictly equal to AI (though I'd gladly believe he didn't actually meant to say that).
AI itself boils down to "Build some lattices, construct a Galois Connection between them and add some abstract transfer function on top of it" (and make sure that all the necessary correctness equations hold; this is the difficult part). For SE you then choose the appropriate lattices and construct suitable transfer functions.
BTW: SE usually also needs a fixed-point iteration to produce meaningful results. At least when considering cyclic control flow graphs (loops & recursion).