Re: ?? Functional Dependency Question ??

On Oct 21, 8:15 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> David BL wrote:
>
> ...
>
> > RTP: (X->A)(Y->B) -> XY->AB
>
> > (X->A)(Y->B) : premise
> > X->A, Y->B : conjunction elimination
> > XY : premise
> > X,Y : conjunction elimination
> > A : modus ponens on X,X->A
> > B : modus ponens on Y,Y->B
> > AB : conjunction introduction
> > XY->AB : conditional proof
> > (X->A)(Y->B) -> XY->AB : conditional proof
>
> I can see that the second step is eliminating a "conjunction" but the
> fourth step doesn't seem to me to involve a conjunction.

Step 3: Premise XY (the conjunction of X and Y). Step 4: From XY deduce X and deduce Y (known as conjunction elimination). Received on Tue Oct 21 2008 - 15:53:15 CEST