Hi,

I'd like to try converting the equality to SUBSET form by using

Pred_setTheory.SUBSET_ANTISYM (THEOREM)
---------------------------------------
|- !s t. s SUBSET t /\ t SUBSET s ==> (s = t)

and then use property like

topology_hvgTheory.BIGUNION_MONO_IMAGE (THEOREM) [1]
------------------------------------------------
|- (!x. x IN s ==> f x SUBSET g x) ==>
   BIGUNION (IMAGE f s) SUBSET BIGUNION (IMAGE g s)


This way you can figure out the relation between 'f' and 'g'...

[1] http://hvg.ece.concordia.ca/code/hol/DFT/index.php

On Sat, Sep 15, 2018 at 4:27 PM Chun Tian (binghe) <binghe.l...@gmail.com>
wrote:

> Hi,
>
> I have a need to prove that, for two certain functions f, (g :num->’a set)
>
>         BIGUNION (IMAGE f 𝕌(:num)) = BIGUNION (IMAGE g 𝕌(:num))
>
> Following its informal proof, it seems only possible to prove the
> following result (by induction) first:
>
>         !(n :num). BIGUNION (IMAGE f (count n)) = BIGUNION (IMAGE g (count
> n))
>
> but once I got this intermediate result, how I can reach to the original
> statement? Is there any other assumption needed for going from finite to
> infinite union?
>
> Thanks,
>
> Chun Tian
>
> _______________________________________________
> hol-info mailing list
> hol-info@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/hol-info
>


-- 
Waqar Ahmad, Ph.D.
Post Doc at Hardware Verification Group (HVG)
Department of Electrical and Computer Engineering
Concordia University, QC, Canada
Web: http://save.seecs.nust.edu.pk/waqar-ahmad/
_______________________________________________
hol-info mailing list
hol-info@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/hol-info

Reply via email to