Re: A Revolution of Logic Reasoning--A Method of Law Free Reasoning


Jan Burse wrote:
Conbra wrote:
Jan Burse wrote:
Simple abduction example:
p->x, q->x, ? |- x
?=p, q, etc..
From premises p -> x, q -> x and x' the results may be p' or q'
that is true. But it also may be "p @ q" that is calculated from
The meaning of the operation @ is "be the same of" or "equal
to".

"be the same of" is normally expressed by the
biconditional <-> instead of your new sign @.

Unfortunately it does not hold:

p->x, q->x, p<->q |- x

So p<->q is not an abductive result for ?.
The counterexample being a model with p=0,
q=0 and x=0.

Bye

From
p->x, q->x, x' |- ?
gets formula
((p -> x,) & (q -> x) & x') |- (p <-> q)
is tautology.

.

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