Thinking along those same lines, here are a couple interesting definitions: -- If there is an occurrence, return the time of the first occurrence, -- otherwise return +infty firstETime :: Ord t => EventG t a -> Time t firstETime = futTime . eFuture -- If there is an occurrence, return the time of the first occurrence, -- otherwise return _|_. firstETime2 :: Ord t => EventG t a -> Time t firstETime2 = firstE . withTimeGE_ On Wed, Nov 19, 2008 at 5:07 PM, David Sankel wrote:

Consider these two events:

a = [] b = [(+infty, _|_)]

Semantically, a and b are different values. Consider their representations in reactive:

a = Event (Future ((Max MaxBound), (_|_))) b = Event (Future ((Max MaxBound), (_|_ `Stepper` a))))

At the end of an event, the second element of the future tuple is bottom. Conversely, the second element of the future tuple is never bottom when not at the end of an event.

There's no particular point to this post, just musing on my discovery of the above facts.

-- David Sankel Sankel Software

-- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office) 585 309 2016 (Mobile)