Prove the 2nd axiom of mathematical logic using the Deduction Theorem

AI Thread Summary
The discussion focuses on proving the second axiom of mathematical logic, which states that if P implies (Q implies R), then if P implies Q, it follows that P implies R. Participants emphasize the importance of using the Deduction Theorem for this proof. There's a consensus that axioms are foundational and should precede theorems in logical reasoning. Some users express skepticism about attempting the proof in reverse, suggesting that progress should be shared for constructive feedback. The conversation highlights the structured approach necessary for logical proofs in mathematical contexts.
solakis1
Messages
407
Reaction score
0
prove:
The 2nd axiom of mathematical logic

2) $((P\implies(Q\implies R))\implies((P\implies Q)\implies(P\implies R))$

By using only the deduction theorem
 
Mathematics news on Phys.org
Axioms come before theorems so there isn't much point, but if you still want to do this backwards then show us what progress you have made.
 
Thread 'Video on imaginary numbers and some queries'
Hi, I was watching the following video. I found some points confusing. Could you please help me to understand the gaps? Thanks, in advance! Question 1: Around 4:22, the video says the following. So for those mathematicians, negative numbers didn't exist. You could subtract, that is find the difference between two positive quantities, but you couldn't have a negative answer or negative coefficients. Mathematicians were so averse to negative numbers that there was no single quadratic...
Thread 'Unit Circle Double Angle Derivations'
Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality...
Thread 'Imaginary Pythagoras'
I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...

Similar threads

Back
Top