From pycyn@aol.com Tue Mar 19 09:51:19 2002 Return-Path: X-Sender: Pycyn@aol.com X-Apparently-To: lojban@yahoogroups.com Received: (EGP: unknown); 19 Mar 2002 17:51:19 -0000 Received: (qmail 96745 invoked from network); 19 Mar 2002 17:25:35 -0000 Received: from unknown (66.218.66.216) by m8.grp.scd.yahoo.com with QMQP; 19 Mar 2002 17:25:35 -0000 Received: from unknown (HELO imo-r09.mx.aol.com) (152.163.225.105) by mta1.grp.scd.yahoo.com with SMTP; 19 Mar 2002 17:25:35 -0000 Received: from Pycyn@aol.com by imo-r09.mx.aol.com (mail_out_v32.5.) id 4.cf.14304138 (4533) for ; Tue, 19 Mar 2002 12:24:56 -0500 (EST) Message-ID: Date: Tue, 19 Mar 2002 12:24:55 EST Subject: Re: [lojban] Logic course To: lojban@yahoogroups.com MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_cf.14304138.29c8ce67_boundary" X-Mailer: AOL 7.0 for Windows US sub 118 From: pycyn@aol.com X-Yahoo-Group-Post: member; u=2455001 X-Yahoo-Profile: kaliputra --part1_cf.14304138.29c8ce67_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/19/2002 9:52:05 AM Central Standard Time, gordon.dyke@bluewin.ch writes: > 1){roda de zo'u li da su'i de du li no} > (can only da de and di (w/ subscripts) be used as bound variables ?) what > does > 1'){roxy. zy. zo'u li xy su'i zy. du li no} mean ? the same as 1)? > Apparently only {da, de, di} . {xy} and so on are anaphoric pronouns and will pick up other things. BUT in a clearly MEX environment, they function as variables, for reading formulae. Question: How tell that this is a clearly MEX environment. I think it is, since there is a formula to read: < 1)AxEy(x + y = 0)> Further, the parser (do check this always) rejects {li da} out of hand, so use either just {da}, etc. throughout or {li xy} Disputable, but the reasonable answer is: to the end of the scope of its binding. In non-formulaic Lojban we fudge a bit after that. <2)AxAyAz(x + y = x + z = 0 => y = z) 2){roda rode rodi zo'u du li da su'i de li da su'i di li no .inaja du li de li di} this can also be written 2') {roda su'epada zo'u du li da su'i de li no}, but we are just starting and are not working with languages as powerfull as lojban yet .uinai> Same problem with {li da} as before. I think you need {fa} in front of the right-shifted first arguments: {roda rode rodi zo'u du fa da su'i de da su'i di li no .inaja du fa de di} This still does not work: {du} is a two-place argument, so the three place version does not work; you need {roda rode rodi zo'u du fa da su'i de da su'i di ije du fa da su'i di li no .inaja du fa de di} And finally, the parser does not see {da su'i de} etc. as sumti, but takes the {da} and puzzles about the rest. I wonder if it goes better with {xy}, etc. {su'epa de} and I think the default on {su'e} is {pa}, so just {su'e de}. <3)Ey(x = y * y) 3){da zo'u li xy. du li da pi'i da}> Still doesn't get {pi'i da} nor {li da}. I expect that this is true (mut mut) for 4 as well. And 5. <5)Ax(Ez(x = z**2) => Ey(x = y * 4)) 5){roda zo'u de zo'u li da du li de te'a re .inaja di zo'u li da du li di pi'i vo}> An argument for forethought connectives, though I think this works out right. And you could skip the internal preneces. But, perversely, {vo} needs a {li}. I think part of the problem is the mixture of MEX, which is for reading a formula, with ordinary Lojban, which is about saying what the formula means. They do not mix well. I suspect that all the {su'i} etc. expressions need a descriptor in ordinary Lojban, something like {me'o}: {li xy du me'o da pi'i da} seems to work somewhat better (it still fails, but I am begining to suspect that the parser doesn't do MEX any better than we do). --part1_cf.14304138.29c8ce67_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/19/2002 9:52:05 AM Central Standard Time, gordon.dyke@bluewin.ch writes:

1){roda de zo'u li da su'i de du li no}
(can only da de and di (w/ subscripts) be used as bound variables ?) what
does
1'){roxy. zy. zo'u li xy su'i zy. du li no} mean ? the same as 1)?

Apparently only {da, de, di} . {xy} and so on are anaphoric pronouns and will pick up other things. BUT in a clearly MEX environment, they function as variables, for reading formulae. Question: How tell that this is a clearly MEX environment. I think it is, since there is a formula to read: <1)AxEy(x + y = 0)>

Further, the parser (do check this always) rejects {li da} out of hand, so use either just {da}, etc. throughout or {li xy}

<how long do bound variables last, if propositions are logically connected ?>

Disputable, but the reasonable answer is: to the end of the scope of its binding. In non-formulaic Lojban we fudge a bit after that.

<2)AxAyAz(x + y = x + z = 0 => y = z)
2){roda rode rodi zo'u du li da su'i de li da su'i di li no .inaja du li de
li di} this can also be written
2') {roda su'epada zo'u du li da su'i de li no}, but we are just starting
and are not working with languages as powerfull as lojban yet .uinai>

Same problem with {li da} as before. I think you need {fa} in front of the right-shifted first arguments: {roda rode rodi zo'u du fa da su'i de da su'i di li no .inaja du fa de
di} This still does not work: {du} is a two-place argument, so the three place version does not work; you need {roda rode rodi zo'u du fa da su'i de da su'i di ije du fa da su'i di li no .inaja du fa de di}
And finally, the parser does not see {da su'i de} etc. as sumti, but takes the {da} and puzzles about the rest. I wonder if it goes better with {xy}, etc.

{su'epa de} and I think the default on {su'e} is {pa}, so just {su'e de}.

<3)Ey(x = y * y)
3){da zo'u li xy. du li da pi'i da}>

Still doesn't get {pi'i da} nor {li da}. I expect that this is true (mut mut) for 4 as well.
And 5.
<5)Ax(Ez(x = z**2) => Ey(x = y * 4))
5){roda zo'u de zo'u li da du li de te'a re .inaja di zo'u li da du li di
pi'i vo}>

An argument for forethought connectives, though I think this works out right. And you could skip the internal preneces. But, perversely, {vo} needs a {li}.

I think part of the problem is the mixture of MEX, which is for reading a formula, with ordinary Lojban, which is about saying what the formula means. They do not mix well. I suspect that all the {su'i} etc. expressions need a descriptor in ordinary Lojban, something like {me'o}: {li xy du me'o da pi'i da} seems to work somewhat better (it still fails, but I am begining to suspect that the parser doesn't do MEX any better than we do).

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