New section of abstraction paper

[cowan@snark.thyrsus.com (John Cowan)]

12. Event-Type Abstractors And Event Contour Tenses

This section is a logical continuation of Section 3.

There exists a relationship between the four types of events explained
in Section 3 and the event contour tense cmavo of selma'o ZAhO.
The specific cmavo of NU and of ZAhO are mutually interdefining; the
ZAhO contours were chosen to fit the needs of the NU event types and
vice versa.  Event contours are explained in full elsewhere, and only
summarized here.

The purpose of ZAhO cmavo is to represent the natural portions of an
event, such as the beginning, the middle, and the end.  They fall into
several groups:

	The cmavo "pu'o", "ca'o", and "ba'o" represent spans of
	time: before an event begins, while it is going on, and
	after it is over, respectively.

	The cmavo "co'a", "de'a", "di'a", and "co'u" represent
	points of time: the start of an event, the temporary
	stopping of an event, the resumption of an event after
	a stop, and the end of an event, respectively.  Not all
	events have breaks in them, in which case "de'a" and "di'a"
	do not apply.

	The cmavo "mo'u" and "za'o" correspond to "co'u" and "ba'o"
	respectively, in the case of those events which have a
	natural ending point that may not be the same as the
	actual ending point:  "mo'u" refers to the natural ending
	point, and "za'o" to the time between the natural ending
	point and the actual ending point (the "excessive" or
	"superfective" part of the event).

	The cmavo "co'i" represents an entire event considered
	as a point-event or achievement.

All these cmavo are applicable to events seen as processes and abstracted
with "pu'u".  Only processes have enough internal structure to make
all these points and spans of time meaningful.

For events seen as states and abstracted with "zu'o", the meaningful
event contours are the spans "pu'o", "ca'o", and "ba'o"; the starting
and ending points "co'a" and "co'u", and the achievement contour "co'i".
States do not have natural endings distinct from their actual ending.
[It is an open question whether states can be stopped and resumed.]

For events seen as activities and abstracted with "za'i", the meaningful
event contours are the spans "pu'o", "ca'o", and "ba'o", and the achievement
contour "co'i".  Because activities are inherently cyclic and repetitive,
the beginning and ending points are not well-defined: you do not know
whether an activity has begun until it begins to repeat.

For events seen as point-events and abstracted with "mu'e", the meaningful
event contours are the spans "pu'o" and "ba'o" but not "ca'o" (a point-event
has no duration), and the achievement contour "co'i".

Note that the parts of events are themselves events, and may be treated
as such.  The points in time may be seen as "mu'e" point-events; the spans
of time may constitute processes or activities.  Therefore, Lojban allows us
to express processes within processes, activities within states, and many
other complicated abstract things.

-- 
John Cowan	cowan@snark.thyrsus.com		...!uunet!lock60!snark!cowan
			e'osai ko sarji la lojban.