Big problem with an update

[Bruno Wolff III]

On Fri, May 24, 2013 at 22:35:14 -0400,
   Frank McCormick <beacon at videotron.ca> wrote:
>I was updating Fedora 19 tonight when my system crashed ( I suspect 
>it's a memory error)....but anyway it
>now **appears I have a lot of duplicate files on my system, at least 
>that what yum check all reports.
>The crash happened after the updates had been installed I think 
>during the verify stage.

Have you tried yum-complete-transaction? That will probably work.
You can check things afterwords with package-cleanup --dupes and 
package-cleanup --problems.