Proof of p^(qvr) <=> (p^q)v(p^r)

[evagelos]

How do we prove in propositional calculus :

...p^(qvr) <===> (p^q)v(p^r) semantically and syntactically

 

[CompuChip]

Well, what have you already come up with?

 

[HallsofIvy]

Comparing truth tables will do it quickly and neatly. Are you not allowed to use that method?

 

[CompuChip]

I had to Google as well, as far as I http://www.rci.rutgers.edu/~cfs/472_html/Logic_KR/proplogic_proofs472.html , using truth tables would be the semantic proof.

 

[evagelos]

Semantical proof without using true tables ,i have one in mind but i am not very positive about it.Then syntactically how about a contradiction you think it could work ,although it looks a bit messy

 

[CompuChip]

It is not quite clear to me what you mean by a semantical proof, and a syntactical one.
Also, if you would post your idea we can have a look at it. Maybe you are on the right track but just need a last push, or maybe you even got it right but lack the confidence