Re: "Semantics" vs. "No Semantics"

From: "Obrst, Leo J." <lobrst@mitre.org>
Subject: RE: "Semantics" vs. "No Semantics"
Date: Mon, 8 May 2006 18:21:13 -0400

> There are three ways to define the semantics, two formal, one informal:
> 1) proof theory: axioms; this is typically harder than (2)
                                                         ^^^ I'm not so
                                                             sure of this
> 2) model theory
> 3) a natural language description describing the operational semantics.
>
> Of course a 4th way is some combination of these.
>
> What else is there?

Well, there are various abstract machine semantics, including the ones for
Prolog and PDP-11s, to pick two quite different examples.  One can make
operational semantics as formal as one wants, including using a very formal
theory of computation such as Turing machines or the lambda or pi calculi
and a very formal mapping from syntax into this target.  Many modern
programming languages have a formal semantics in this style.

> Thanks,
> Leo

peter