From: Douglas Gregor (gregod_at_[hidden])
Date: 2002-09-06 09:30:37
On Friday 06 September 2002 10:13 am, Joel Young wrote:
> Could you give me an example of two intervals and a relop you consider
> indeterminate?
Sure. [3, 5] <= [4, 6] is indeterminate, because 3 <= 5 but !(5 <= 4).
> What does the ":=" symbol mean? iff?
Yes, iff.
> [a,b] RelOp [c,d] :=
> x RelOp y for all (x, y) where a <= x <= c, b <= y <= d
>
> I think for three-valued logic, the above definition isn't sufficient.
> Am I missing something?
I should rephrase that:
[a,b] RelOp [c,d] iff Conjunction of x RelOp y for all (x, y) where a <= x
<= c, b <= y <= d
(Conjunction is the 3-valued logic conjunction).
Is that clearer?
Doug