From pycyn@aol.com Mon Aug 12 09:08:44 2002 Return-Path: X-Sender: Pycyn@aol.com X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-8_0_7_4); 12 Aug 2002 16:08:44 -0000 Received: (qmail 41194 invoked from network); 12 Aug 2002 16:08:43 -0000 Received: from unknown (66.218.66.217) by m15.grp.scd.yahoo.com with QMQP; 12 Aug 2002 16:08:43 -0000 Received: from unknown (HELO imo-r03.mx.aol.com) (152.163.225.99) by mta2.grp.scd.yahoo.com with SMTP; 12 Aug 2002 16:08:43 -0000 Received: from Pycyn@aol.com by imo-r03.mx.aol.com (mail_out_v33.5.) id r.60.243ee51d (3924) for ; Mon, 12 Aug 2002 12:08:32 -0400 (EDT) Message-ID: <60.243ee51d.2a893780@aol.com> Date: Mon, 12 Aug 2002 12:08:32 EDT Subject: RE: Tenses To: lojban@yahoogroups.com MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_60.243ee51d.2a893780_boundary" X-Mailer: AOL 7.0 for Windows US sub 10509 From: pycyn@aol.com X-Yahoo-Group-Post: member; u=2455001 X-Yahoo-Profile: kaliputra --part1_60.243ee51d.2a893780_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Before dealing with various points about Lojban tenses, I find it helpful to review the ideal system and its (partial) realizations in logic, natural languages and Lojban. This gives an anchor to cling to when the controversies get too confusing. So: Tense is a system of vectors that run from axes to events. An axis comes into existence by having a vector originate at it, an event comes into language by being at the end of a vector. Vectors have two properties: a direction and a length (tensor). In tense vector systems there is a 0-vector, which ends where it originates and has a length of (conventionally) 0 in every measuring system. Vectors can iterate; that is, the "event" at which one vector ends may be simply the start of another vector, a new axis. The direction of a vector may be given in any of a number of intertranslatable (given some some faaactual information) forms, based on a variety of techniques: graph points, angles, egocentric directions, geographical directions, direction of known objects, indexicals, and so on. In the case of temporal vectors, there are only the three directions, past (-), present (0), and future (+) and the reference to a known event, but spatial vectors can be specified in a bewildering variety of ways. The same is true of tensors, which can be specified numerically according to some system of measurement or by reference to some known thing and even by reference to the other modality (times can be referenced spatially and spaces temporally). The system also allows "events" that are either outside time (to which time is irrelevant -- eternal) or simply "occur" at all times (sempiternal) and similarly for space (ellocal and ubiquitous). The first axis of a string of one or more vectors is usually taken as given: either the here-and-now of the speaker or something established by context. It might also be given explicitly by some name or description, including some vector from the given axis. A vector may be indicated only partially: either the tensor or the direction may be omitted or given in a vague way ("a long time" vs. "seven and a half hours," for example), and, in spatial tenses, some dimensions may be ignored (we omit altitude in giveing street directions, say). Tense logical systems tend to be either very vague or (in principle) very precise on tensors, precise on direction and to use vectors to define new axes. They also (I think because they are generally not predicate logical systems), tend to ignore the 0-vector, not distinguishing among, for example, -, 0- and -0 temporal vector strings, as some natural languages do. In logic, unmarked sentences are typically of the outside or always variety (which, combined with the absence of the 0-vector creates problems, usually dealt with by introducing a name for the implicit initial axis). Vectors are indefinitely iterable in logic, whereas natural languages seem never to have more than four temporal vectors in a single string and even that extreme case is often a little peculiar, starting to flop outside the tense system. The natural systems of spatial tenses is less clear but, on other than observed grounds, probably does not allow more than seven vectors in a single string. Logic systems typically (for control) use a limited number of ways to describe directions, measure tensors and introduce new axes; natural languages seem to allow just about all the ways that one can think (in that language -- a SW effect?). Lojban has a full basic temporal tense system: {pu} -, {ca} 0, {ba} +, and a set of vague tensors,ZI. It has a spatial 0 {bu'u} and a variety of directional device: egocentric and geographic (much of FAhA, the rest of which I save for another time) and another set of vague tensors VI. The directional markers of a given type may be iterated indefinitely (though again, I suspect that seven is a practical upper limit and pushing one's luck at that), but the iterations cannot be mixed either temporals and spatials. There can be both a temporal string and a spatial one but they are separate. There can be a string of directionals, or of directional+distance (in that order) combinations, but not, apparently, of more than one distance nor of a moixture of directionals and distances, except for a distance-initial string of directionals. Unmarked sentences may be of any type, outside-or-all-over or at a contextually determned axis -- context decides (Grice rules!). Remote axes that are explicit are introduced by name or description of a coincident event or object, not by displacement from the given axis (except as that might be worked into a name or description). Thje standard way of using a remote axis is parallel to using the given one, except the reference to the axis is explicit: {vi le cmana [ku]} means "a short way from the mountain", just as {vi [ku]} means "a short way from the given axis" and the longer expression has about the same range of locations as the shorter one and, like it, needs some care to keep its connection with the whole sentence rather than some sumti within it. A remote axis expression cannot, therefore, go in the normal tense place, since it will there attach to the x1 sumti (and putting {cu} before it is illegal). For the discussion at hand, the point to notice is that in tense+sumti, the sumti is always an axis, never an event: {pu lenu mi broda} means "before I broda," never "back when I broda" or an equivalent of {mi pu broda}. This meets the present problem; the others (like "How do you give precise tensors, e.g., 'fifty minutes ago and five miles away'?") will have to wait. --part1_60.243ee51d.2a893780_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit Before dealing with various points about Lojban tenses, I find it  helpful to review the ideal system and its (partial) realizations in logic, natural languages and Lojban.  This gives an anchor to cling to when the controversies get too confusing.  So:
Tense is a system of vectors that run from axes to events.  An axis comes into existence by having a vector originate at it, an event comes into language by being at the end of a vector.  Vectors have two properties: a direction and a length (tensor). In tense vector systems there is a 0-vector, which ends where it originates and has a length of (conventionally) 0 in every measuring system.  Vectors can iterate; that is, the "event" at which one vector ends may be simply the start of another vector, a new axis. The direction of a vector may be given in any of a number of intertranslatable (given some some faaactual information) forms, based on a variety of techniques: graph points, angles, egocentric directions, geographical directions, direction of known objects, indexicals, and so on.  In the case of temporal vectors, there are only the three directions, past (-), present (0), and future (+) and the reference to a known event, but spatial vectors can be specified in a bewildering variety of ways.  The same is true of tensors, which can be specified numerically according to some system of measurement or by reference to some known thing and even by reference to the other modality (times can be referenced spatially and spaces temporally).  The system also allows "events" that are either outside time (to which time is irrelevant -- eternal) or simply "occur" at all times (sempiternal) and similarly for space (ellocal and ubiquitous).  The first axis of a string of one or more vectors is usually taken as given: either the here-and-now of the speaker or something established by context.  It might also be given explicitly by some name or description, including some vector from the given axis.  A vector may be indicated only partially: either the tensor or the direction may be omitted or given in a vague way ("a long time" vs. "seven and a half hours," for example), and, in spatial tenses, some dimensions may be ignored (we omit altitude in giveing street directions, say). 
Tense logical systems tend to be either very vague or (in principle) very precise on tensors, precise on direction and to use vectors to define new axes.  They also (I think because they are generally not predicate logical systems), tend to ignore the 0-vector, not distinguishing among, for example,  -, 0- and -0 temporal vector strings, as some natural languages do. In logic, unmarked sentences are typically of the outside or always variety (which, combined with the absence of the 0-vector creates problems, usually dealt with by introducing a name for the implicit initial axis).  Vectors are indefinitely iterable in logic, whereas natural languages seem never to have more than four temporal vectors in a single string and even that extreme case is often a little peculiar, starting to flop outside the tense system.  The natural systems of spatial tenses is less clear but, on other than observed grounds, probably does not allow more than seven vectors in a single string.  Logic systems typically (for control) use a limited number of ways to describe directions, measure tensors and introduce new axes; natural languages seem to allow just about all the ways that one can think (in that language -- a SW effect?).
Lojban has a full basic temporal tense system: {pu} -, {ca} 0, {ba} +, and a set of vague tensors,ZI. It has a spatial 0 {bu'u} and a variety of directional device:
egocentric and geographic (much of FAhA, the rest of which I save for another time) and another set of vague tensors VI. The directional markers of a given type may be  iterated indefinitely (though again, I suspect that seven is a practical upper limit and pushing one's luck at that), but the iterations cannot be mixed either temporals and spatials. There can be both a temporal string and a spatial one but they are separate.  There can be a string of directionals, or of directional+distance (in that order) combinations, but not, apparently, of more than one distance nor of a moixture of directionals and distances, except for a distance-initial string of directionals.
Unmarked sentences may be of any type, outside-or-all-over or at a contextually determned axis -- context decides (Grice rules!).  Remote axes that are explicit are introduced by name or description of a coincident event or object, not by displacement from the given axis (except as that might be worked into a name or description).  Thje standard way of using a remote axis is parallel to using the given one, except the reference to the axis is explicit: {vi le cmana [ku]} means "a short way from the mountain", just as {vi [ku]} means "a short way from the given axis" and the longer expression has about the same range of locations as the shorter one and, like it, needs some care to keep its connection with the whole sentence rather than some sumti within it.  A remote axis expression cannot, therefore, go in the normal tense place, since it will there attach to the x1 sumti (and putting {cu} before it is illegal).
For the discussion at hand, the point to notice is that in tense+sumti, the sumti is always an axis, never an event: {pu lenu mi broda} means "before I broda," never "back when I broda" or an equivalent of {mi pu broda}. This meets the present problem; the others (like "How do you give precise tensors, e.g., 'fifty minutes ago and five miles away'?") will have to wait. --part1_60.243ee51d.2a893780_boundary--