[FOM] Bivalence and Law of Excluded Middle

[Larry Stout]

Certainly one can do mathematics in a Boolean-valued model in which  
one does have the law of the excluded middle but does not have  
bivalence in the sense of having only two truth values.

If the statement of bivalence is [[p \vee \lnot p]] = true  then it  
would seem to say exactly the law of excluded middle.

If the statement of bivalence is [[p]]=true or [[\lnot p]]=true then  
it certainly does not.

Is the 'or' in the definition of definiteness from Sayward
	"Call a statement truth definite if it or its negation is true."
in the metalanguage or in the object language?

Larry Stout


On Feb 18, 2008, at 9:22 AM, Joseph Vidal-Rosset wrote:
>
> I would be happy to hear the opinions and the arguments of FOM
> subscribers about the question that Sayward asked in the title of this
> paper. Does the LEM require Bivalence?
>