MHB Intro to Logic (prove sequents)

  • Thread starter Thread starter kk12
  • Start date Start date
  • Tags Tags
    Intro Logic
kk12
Messages
1
Reaction score
0
I am stuck on these questions and don't really know how to start/solve them.
prove the following sequent:
1. $(\exists x) Fx \to (\forall x) Gx \vdash (\exists x)(Fx \to (\forall x)Gx)$

2. $(\forall x)(Fx \to (\forall y)\neg Fy) \vdash \neg(\exists x)Fx$

3. $(\exists x)Fx, (\forall x)(Fx \; à \; Gx) \vdash (\exists x)G$
 
Physics news on Phys.org
See this https://driven2services.com/staging/mh/index.php?threads/29/.
 

Thread 'Roulette wheel physics and probability'

Hi all, I've been a roulette player for more than 10 years (although I took time off here and there) and it's only now that I'm trying to understand the physics of the game. Basically my strategy in roulette is to divide the wheel roughly into two halves (let's call them A and B). My theory is that in roulette there will invariably be variance. In other words, if A comes up 5 times in a row, B will be due to come up soon. However I have been proven wrong many times, and I have seen some...
View full post »
Thread 'Detail of Diagonalization Lemma'

Thread 'Detail of Diagonalization Lemma'

The following is more or less taken from page 6 of C. Smorynski's "Self-Reference and Modal Logic". (Springer, 1985) (I couldn't get raised brackets to indicate codification (Gödel numbering), so I use a box. The overline is assigning a name. The detail I would like clarification on is in the second step in the last line, where we have an m-overlined, and we substitute the expression for m. Are we saying that the name of a coded term is the same as the coded term? Thanks in advance.
View full post »

Similar threads

MHB Proving First Order Logic in Machover's Text
Replies
1
Views
1K
MHB How Do We Find the Logical Negation of Statements?
Replies
6
Views
1K
MHB Help with Logic Proof: Establishing 7.
Replies
1
Views
1K
MHB Can Predicate Logic Capture Complex Human Reasoning?
Replies
3
Views
2K
MHB Upper Bound of Sets and Sequences: Analyzing Logic
Replies
3
Views
5K
Union of sets and indexed sets question from Vellerman
Replies
4
Views
1K
MHB Predicate logic with multiple quantifiers
Replies
2
Views
2K
I Logic Game: Abelard & Heloise - Naturals xu-yt > v^z
Replies
17
Views
2K
The Logic of the Principia Mathematica
Replies
1
Views
1K
MHB Solution: Proving Existence of x for Logic Formal Proof
Replies
4
Views
5K

Hot Threads

Recent Insights

Back
Top