# S.O.S. Mathematics CyberBoard

Your Resource for mathematics help on the web!
 It is currently Thu, 8 Dec 2016 03:06:23 UTC

 All times are UTC [ DST ]

 Page 1 of 1 [ 3 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Propositional LogicPosted: Thu, 4 Feb 2010 14:50:33 UTC
 S.O.S. Newbie

Joined: Thu, 4 Feb 2010 14:45:45 UTC
Posts: 3
I am having serious trouble with proving this sequent and would appreciate some help!

: ((P → ~ P) → P) → ((P → ~ P) → ~ P)

it must be achieved in ten steps, and is a theorem so has no premises

Thanks guys!!

Top

 Post subject: Re: Propositional LogicPosted: Thu, 4 Feb 2010 19:04:45 UTC
 Moderator

Joined: Mon, 29 Dec 2008 17:49:32 UTC
Posts: 7624
Location: NCTS/TPE, Taiwan
MissSarahLee wrote:
I am having serious trouble with proving this sequent and would appreciate some help!

: ((P → ~ P) → P) → ((P → ~ P) → ~ P)

it must be achieved in ten steps, and is a theorem so has no premises

Thanks guys!!

Don't know exactly which rules you are allowed to use, but a way to prove the statement is first proving , then apply and modus ponens.

_________________

Last edited by outermeasure on Thu, 4 Feb 2010 19:13:27 UTC, edited 1 time in total.

Top

 Post subject: hmmPosted: Thu, 4 Feb 2010 19:10:16 UTC
 S.O.S. Newbie

Joined: Thu, 4 Feb 2010 14:45:45 UTC
Posts: 3
Im not entirely sure about that, im not learning such advanced stuff yet

currently i am using the basic rules, such as & elimination and introduction, conditional proof, reductio ad absurdum, disjunction elimination and introduction, modus ponens, modus tolens, biconditional introduction and elimination and basic propositional logic like that, thanks for your reply though:)

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 3 posts ]

 All times are UTC [ DST ]

#### Who is online

Users browsing this forum: No registered users

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forum

Search for:
 Jump to:  Select a forum ------------------ High School and College Mathematics    Algebra    Geometry and Trigonometry    Calculus    Matrix and Linear Algebra    Differential Equations    Probability and Statistics    Proposed Problems Applications    Physics, Chemistry, Engineering, etc.    Computer Science    Math for Business and Economics Advanced Mathematics    Foundations    Algebra and Number Theory    Analysis and Topology    Applied Mathematics    Other Topics in Advanced Mathematics Other Topics    Administrator Announcements    Comments and Suggestions for S.O.S. Math    Posting Math Formulas with LaTeX    Miscellaneous