Thank you again for the assistance and education. I will be more careful with my test data next time. The system locks up whenever I try to post anything too long, so here is my shortened version

with ordered as (

select d.a, d.b, d.dte

, _a = lag(a, 1, null) over (order by a, dte)

, _b = lag(b, 1, null) over (order by a, dte)

from #date d)

select *

from ordered o

where not exists (select o.a, o.b

intersect

select o._a, o._b);