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Questions tagged [fitch-proofs]

11 questions
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Fitch Format Proofs - Any automatic solvers around?

Is there any software around that using the Fitch format (used in Language, Proof and Logic), allows one to put a specific set of premises and goals and have it show us the full list of steps needed to solve the problem?
devoured elysium
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Given ((p ⇒ q) ⇒ r), use the Fitch system to prove ((p ⇒ q) ⇒ (p ⇒ r))

I am trying, given ((p ⇒ q) ⇒ r),, to use the Fitch System in order to prove ((p ⇒ q) ⇒ (p ⇒ r)). Any ideas on how I should proceed?
Phani
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How would one prove ((p ⇒ q) ⇒ p) ⇒ p, using the Fitch system

FYI, the logic program I use cannot do contradiction introductions. This point is most likely irrelevant, for I highly doubt I would need to use any form of contradiction for this proof. In my attempt to solve this, I started off with assuming (p ⇒…
God's Drunkest Driver
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Fitch-Style Proof

Hi I'm having trouble solving a Fitch Style Proof and I was hoping someone would be able to help me. Premises: A ^ (B v C) B => D C => E Goal: ~E => D
user3727903
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Why is Q → P a logical consequence of ¬(P → Q )

I don't want to ask my professor about this because I'm awful at this and he's not the, uhh, patient type of professor to say the least. ANYWAY, it was my understanding that ¬(P → Q ) and (¬P → ¬Q ) mean two different things. And that Q → P is equal…
Daniel K.
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Deriving Cube(a) from Cube(a) <-> a = a (Fitch)

I'm trying to prove something in Fitch and i'm stuck on one step, i have: 1. Cube(a) <-> a = a and i want to derive 2. Cube(a) from that. I know it's possible because i can use Ana Con on 2. and selecting 1. as premise and it says it's valid. Is…
Aerus
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Formal proof for ((p ⇒ q) ⇒ p) ⇒ p

I'm trying to construct a formal proof for ((p ⇒ q) ⇒ p) ⇒ p. in Fitch. I know this is true, but how do I prove it? I can only use And Intro, And Elim, Or Inro, Or Elim, Neg Intro, Neg Elim, Impl Intro, Impl Elim, Biconditional Intro, and…
rodrigo ferreira
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Fitch Format Proofs - any resources around?

I am currently studying Fitch Format first order logic proofs. My lecturer follows closely Language, Proof and Logic by Jon Barwise. I am trying to do some proofs but I am having some trouble getting to understand how to do these proofs. As I have…
devoured elysium
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Formal proof for P → Q ≡ ¬P ∨ Q in Fitch

I'm trying to construct a formal proof for 'P → Q ≡ ¬P ∨ Q' in Fitch. I know this is true, but how do I prove it?
Yaeger
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Logic deduction with Fitch system

I was working through some logic and I found a difficulty I can't solve, How can I proof from the premise p=>q, that ¬q=>¬p? Thank you
user2296563
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working on logic - fitch system

Struggling with logic and fitch system, I am trying, given (p ⇒ ¬q) and (¬q ∧ p ⇒ r) and p, to use the Fitch System in order to prove r. Any ideas on how I should proceed?
user1719345
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