ssn: value add of dul

Dear SDW,
I don't know why, but today in the ssn meeting the question of whether ssn should be aligned to dul or not was brought up again.  I think it was covering old, well-resolved ground that is reflected in our current published WD, but this seems not to be agreed.

Therefore I propose we invite the author of dul (actually DOLCE+DnS Ultralite) Aldo Gangemi to an ssn meeting to present on the virtues/stability/value/users/use etc of dul in association with ssn.

Kerry