Re: identifying entities across database updates
Date: Thu, 16 Jul 2009 07:27:04 -0700 (PDT)
Message-ID: <260cae22-519d-40f9-98c0-5569b0e86558_at_d36g2000prb.googlegroups.com>
On Jul 15, 11:36 am, Tegiri Nenashi <TegiriNena..._at_gmail.com> wrote:
> On Jul 14, 8:06 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
> > Are you saying lambda calculus is more complex?
>
> Complexity is measured by a potential number of bugs. By that criteria
> TM simulator, e.g.
>
> http://math.ucsd.edu/~sbuss/CourseWeb/MathLogic160/NobleJava/NobleJav...
>
> is both complex and fugly.
>
> The underlying TM concepts ("tape", "read/write", "instruction")
> appeal to human intuition, but are by no means clean mathematical
> entities. I noticed my elevated confidence when programming heavily
> mathematical stuff: the code essentially writes itself and the the
> bugs are few and between.
In the mid 30's when Church/Kleene introduced the lambda definable functions and proposed it for a definition of effectively calculable, Godel was unconvinced calling it "thoroughly unsatisfactory" (in a letter to Kleene).
Compare to one of Godel's quotes on Turing's work: "That this really is the correct definition of mechanical computability was established beyond any doubt by Turing.”
In that sense, the TM has been important. Received on Thu Jul 16 2009 - 16:27:04 CEST