On 01 Sep 2009, at 18:46, Flammarion wrote: > > > > On 1 Sep, 17:29, Bruno Marchal <marc...@ulb.ac.be> wrote: >>> >>> >> >> By comp, mainly by Church thesis only, you (in the third person >> sense) >> are implemented in the mathematical UD. OK? > > > The mathemaitcal UD doesn't exist.

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Do you agree that it exists in the mathematical sense? And that all the description of all possible machines going through your current comp states at all your substitution levels, which exist by digital mechanism, are generated in that mathematical structure? Here "generated" has been defined using first order logic language together with the symbole 0, s, +, * and parentheses. It is the level 0 if you want. With comp *any* universal system can be used, the problem is to justifies the "inning quantum computations". With Church thesis I can use elementary arithmetic to implement the computations, notably the universal dovetailer, which really correspond to the finite and infinite proofs of the Sigma_1 sentences (the true and the false). Then you *can* interpret formally all the richer machines' talk simulated by that UD. Their are richer because they are "believing" (and thus using this in their reasoning process) the induction axioms, like Peano Arithmetic. That gives the epistemology, the physical qualia, the physical quanta, the universal knower, the universal doubter, and the "one" which is just arithmetical truth. It does not yet gives the measure, but it gives the logic pertaining on that measure. Do you know modal logic? Are you aware of Solovay double completeness G/G* theorem on the logic of self-reference? I have a question, also, how can you be formalist, and make an ontological commitment? How can you believe in a notion of "ontological existence"? What does that mean for a formalist? Can you give me a formal definition of "ontological existence"? I confess to you, also, that I am not sure that Church thesis, can make sense for a formalist. Funnily, CT is a chance for the formalisms and the machines, but the price (the chance?) is the impossibility to describe completely and formally the truth on formalism and mechanism. It is a chance for the machine, it preserves them against closed formalism or reductionism. This makes us more ignorant (assuming comp, which is just a more precise version than usual CTM, if you want a nuance). I must say that I begin to ask myself if it is sane for me to continue to discuss with someone who goes through the loop: seven does not exist physically seven does not exist ontologically seven does not exist at all seven does not exist seven does not exist physically ... You are free to restrict my use of existence as the use of the existential quantifier introduction rules of first order logic. If I prove to you "prime(s(s(s(0)))", I can deduce "Exprime(x)", in english: there is a prime number, or prime numbers exist. Physical existence is reduced to such formal existence, but the quantifier rules changes for respecting the observable modalities. Themselves can be motivated through your implication in the UDA thought experiences, or can be given by a literal arithmetical interpretation of Theaetetus' theories of knowledge. Bruno http://iridia.ulb.ac.be/~marchal/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---