I am trying to solve this but I am not too sure whether I am doing this right

p V ( q ʌ r)

----------

p V q

and I know this can be proved using V-E rule.

But I just don't know the step maybe because i am new to this thing. Please help me..

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- Aug 6th 2012, 01:15 PMgomdohriNatural Deduction in propositional logic
I am trying to solve this but I am not too sure whether I am doing this right

p V ( q ʌ r)

----------

p V q

and I know this can be proved using V-E rule.

But I just don't know the step maybe because i am new to this thing. Please help me.. - Aug 6th 2012, 02:18 PMemakarovRe: Natural Deduction in propositional logic
There are several flavors of natural deduction: Fitch style, tree style with formulas as nodes and tree style with sequents as nodes. The following is a derivation in tree style with formulas (the picture is clickable).

Attachment 24444

Fee free to ask further questions if this format is not clear. - Aug 6th 2012, 10:12 PMgomdohriRe: Natural Deduction in propositional logic
if you don't mind could you please represent this in Fitch style so that I can check whether I 've got this right? thank you very much Mr. emakarov!

- Aug 7th 2012, 02:26 AMemakarovRe: Natural Deduction in propositional logic
Fitch style is something like this.

Code:`1. p \/ (q /\ r) Assumption`

2. p Assumption

3. p \/ q 2, \/I

4. q /\ r Assumption

5. q 4, /\E

6. p \/ q 5, \/I

7. p \/ q 1,2-3,4-6, \/E

- Aug 7th 2012, 07:05 AMgomdohriRe: Natural Deduction in propositional logic
Thank you for your kindness