This is a `discovery paper' for a CLASS lens system.
This is a pre-copyedited, author-produced version of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record is available at the URLs mentioned on the abstract page, in my publication list, and at the basic-information page for this work.
The links below point to one file containing the complete text, all figures and tables etc.
As are most of my publications this is available in more than one form: