cianfa72's latest activity
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cianfa72 reacted to jedishrfu's post in the thread I Deductive proof in logic formal systems with
Like.
Adding semantics to a formal system doesn’t make it a “formal theory.” A theory involves the addition of specific non-logical axioms... -
cianfa72 replied to the thread I Deductive proof in logic formal systems.Ah ok. So the point is: combining a formal system with a semantics (i.e. assigning an interpretation of the non-logical symbols) results...
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cianfa72 replied to the thread I Deductive proof in logic formal systems.Ah ok, so an expression like ##\Gamma \;\vdash\; \varphi## is an instance of a sequent. As an aside, we can say that a formal system...
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cianfa72 reacted to jedishrfu's post in the thread I Deductive proof in logic formal systems with
Agree.
When a sequent like: ##\Gamma \;\vdash\; \varphi## is used, it means: From the set of assumptions/premises ##\Gamma##, the formula... -
cianfa72 posted the thread I Deductive proof in logic formal systems in Set Theory, Logic, Probability, Statistics.I was reading documentation about the soundness and completeness of logic formal systems. Consider the following $$\vdash_S \phi$$ where...
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cianfa72 replied to the thread I Synchronizing clocks in an inertial frame if light is anisotropic.Yes exactly. For instance this convention does prescribe to reset to 0 the B's clock at event B2 (i.e. label it as T=0 along B's...
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cianfa72 reacted to James Hasty's post in the thread I Synchronizing clocks in an inertial frame if light is anisotropic with Like.
I agree this works, but only because you have defined the convention for the 1-way speed of light in both directions.
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cianfa72 replied to the thread I Synchronizing clocks in an inertial frame if light is anisotropic.Just to clarify the point, I drew the following diagram. The base grid ##(x,t)## represents of course the standard inertial coordinate...
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cianfa72 replied to the thread I Synchronizing clocks in an inertial frame if light is anisotropic.Yes, as far as I can tell the key point is that basically, before the exchange of light signals between observer A and B takes place, it...
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cianfa72 replied to the thread I About the existence of Hamel basis for vector spaces.Yes, this video addresses exactly the point you made.
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cianfa72 replied to the thread I About the existence of Hamel basis for vector spaces.I believe the topic discussed in this thread is well addressed in R. Penrose's book "The Road to Reality". In chapter 1, he discusses...
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cianfa72 replied to the thread I QM Qubit state space representation by Projective Hilbert space.Yes, the above is the "familiar" 2 x 2 matrix representation for the ##S_z## operator (involving the Pauli z-matrix). By changing the...
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cianfa72 replied to the thread I QM Qubit state space representation by Projective Hilbert space.You mean pick a different orthonormal basis in ##\mathcal H_2## mapping they elements to vectors in ##\mathbb C^2## as prescribed by the...
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My training as a network engineer (retired) has been activated... On the face of it, the URL...
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cianfa72 replied to the thread I Describing the Big Bang.Even though the hyperbolic plane can't be embedded isometrically in 3D Euclidean space, can it be isometrically embedded in three...
