Re: Re: Re: Re: Re: RE: Re: Sometimes <space> means multiple

*To*: mathgroup at smc.vnet.net*Subject*: [mg75500] Re: [mg75474] Re: [mg75442] Re: [mg75426] Re: [mg75423] Re: [mg75364] RE: [mg75358] Re: Sometimes <space> means multiple*From*: János <janos.lobb at yale.edu>*Date*: Thu, 3 May 2007 03:46:09 -0400 (EDT)*References*: <200704270918.FAA23598@smc.vnet.net> <200704290714.DAA21234@smc.vnet.net> <200704300738.DAA22373@smc.vnet.net> <200705010719.DAA07230@smc.vnet.net> <200705020751.DAA05016@smc.vnet.net>

Just to be sure I looked up Jen=F6 Erd=F6s selected teachings again at http://www.math.klte.hu/~szekely/Jeno11.pdf and found no usage of "space" or "asterix" or "star" in any shape or form there for multiplication. I could see only nothing or the central point for multiplication. So when someone is claiming that the virtuosity of Mathematica to convert "a b" into "a*b" and vice verse is the best thing after sliced bread, I am not impressed. With the best, J=E1nos P.S. If you can read Hungarian, you will find that the pdf listed above is one of the finest work a real mathematician ever produced. On May 2, 2007, at 3:51 AM, Andrzej Kozlowski wrote: > I think I can see some advantages to "intellectual laziness". It > might, for example, stop people writing long posts when they have no > point to make. > > So to make it short: it was already pointed by someone else that > Mathematica's use of "space" for multiplication is simply the > nearest = > > approximation to using nothing at all - by far the most common > convention in algebra. Mathematica does allow "nothing" to be used > when no ambiguity results; in other cases space is used, which > approximates rather well what one can see in books an d papers on > algebra. > In InputForm asterisk is used because central dot is not available > in = > > ASCII and ordinary dot is used, naturally, for dot product. Asterisk > is sometimes used in books on algebra do denote binary operations, > probably more often than "x" (which can, of course, be used in > TraditionalForm in Mathematica). > Intellectual laziness (presumably due to infection) prevents me from > writing any more on this subject. > > Andrzej Kozlowski > > > On 1 May 2007, at 16:19, J=E1nos wrote: > >> I think the reason for "space" used as multiply is the typical anglo- >> american intellectual laziness :) /Old Hungarian proverb: "Whose >> shirt it is not, should not take it on"/ >> >> Steve just did not want to type an extra character when he came up >> with the design - that is it. He was also constrained by the ASCII == > >> 7 = >> >> bit. >> >> If I look back on my education for multiplication in elementary >> school a dot was use on the "middle of the lane". On a Mac it is >> <Option>+<Shift>+<9>. >> >> Now to use that would have been more painful than just <Shift>+<8>, >> wouldn't it ?. >> >> The <Shift>+<8> came to the math circles via computers and with >> punch = >> >> cards where the restrictive ASCII 7 bit ruled the world and "a" and >> "b" had to be tightened with SOMETHING. >> >> Looking many professional journal pdfs one thing is sure. Neither >> the "space" nor the "star" is used for multiplication. It is still >> the dot on the "middle of the lane", a small "x" or nothing. That >> is, I never see "a*b" or "a b" as a multiplication of a and b but >> rather I see "ab" or "a=B7b". >> >> With the best, >> >> J=E1nos >> P.S. If I take the "a b" to its ultimate test and "try" it in pre- >> fix " ab" or post-fix "ab " that shows clearly the dumbness of the >> usage of space in its pure naked form :) >> >> On Apr 30, 2007, at 3:38 AM, Andrzej Kozlowski wrote: >> >>> I compltely agree. I also think that any comparisons between C++ and >>> Mathematica in this respect are completely off the mark, unless of >>> course sombody decides to develop an analogue of "TradtitionalForm" >>> for C++. >>> >>> I would also like to point out the following obvious but not >>> insignificant fact. Enter a b (or 2 3 if you prefer) and >>> convert to >>> InputForm. You will obtain an explicit asterisk in place of the >>> space. Conversely, enter a*b and convert to TraditionalForm (or even >>> StandardForm). You will get a space instead of the asterisk. >>> This, in >>> my opinion, is exactly how it should be. In fact, I am somewhat >>> shocked that anyone would claim otherwise. >>> >>> Andrzej Kozlowski >>> >>> >>> On 29 Apr 2007, at 16:14, Murray Eisenberg wrote: >>> >>>> Why "mistake"? Why not allow Mathematica to mimic as much of >>>> traditional mathematical notation as possible without running into >>>> genuine ambiguity? >>>> >>>> After all, it's really convenient to be able to use 2 Exp[x] and >>>> Cos[2 >>>> t] -- and even 2Exp[x] and Cos[2t] -- without having to insert an >>>> extra, >>>> distracting multiplication symbol. Then the usage in 2 4, for >>>> example, >>>> just extends that. >>>> >>>> In my own work, I ordinarily include an explicit multiplication >>>> symbol >>>> -- and I prefer the multiplication sign one gets from Esc * Esc >>>> instead >>>> of the FORTRANish * -- when the factors are numbers. There's >>>> nothing to >>>> prevent you from doing that if you don't like the implicit >>>> multiplication indicated by a space. >>>> >>>> >>>> Virgilio, Vincent - SSD wrote: >>>>> Personally, I think it was a mistake to overload the meaning of >>>>> "space" >>>>> to multiply. I bet Wolfram Inc. would reverse that decision now, >>>>> if it >>>>> wasn't for backward compatibility. >>>>> >>>>> I like to compare Mathematica to C++. Somewhere in his writings, >>>>> Bjarne >>>>> Stroustrup mentions the same issue, and his decision not to >>>>> overload >>>>> whitespace. I think the question also arises on the Boost mailing >>>>> lists >>>>> now and then, mostly tongue-in-cheek. >>>>> >>>>> (Corrections welcome.) >>>>> >>>>> Vince Virgilio >>>>> >>>>> -----Original Message----- >>>>> From: Bill Rowe [mailto:readnewsciv at sbcglobal.net] >>>>> Sent: Thursday, April 26, 2007 3:35 AM >>>>> To: mathgroup at smc.vnet.net >>>>> Subject: [mg75364] [mg75358] Re: Sometimes <space> means >>>>> multiple , sometimes not >>>>> >>>>> On 4/25/07 at 5:27 AM, siewsk at bp.com wrote: >>>>> >>>>>> As a newbie, I was taught that <space> character in Mathematica >>>>>> means >>>>>> multiple. But sometimes it does not. >>>>> >>>>>> For example: >>>>> >>>>> <examples snipped> >>>>> >>>>> Mathematica allows spaces to be placed before or after any >>>>> operation. >>>>> Consequently, a space is only interpreted as a multiply when there >>>>> is no >>>>> other operator or other possible interpretation. >>>>> >>>>> So, -4 -2 is the same as -4 - 2 or -4-2 and gives -6 but >>>>> -4 (-2) will yield 8 >>>>> -- >>>>> To reply via email subtract one hundred and four >>>>> >>>>> ***************************************************************** >>>>> This e-mail and any files transmitted with it may be proprietary == >>>>> >>>>> and are intended solely for the use of the individual or entity >>>>> to == >> >>>>> >>>>> whom they are addressed. If you have received this e-mail in = >>>>> >>>>> error please notify the sender. Please note that any views or >>>>> opinions presented in this e-mail are solely those of the author == >>>>> >>>>> and do not necessarily represent those of ITT Corporation. The = >>>>> >>>>> recipient should check this e-mail and any attachments for the = >>>>> >>>>> presence of viruses. ITT accepts no liability for any damage = >>>>> >>>>> caused by any virus transmitted by this e-mail. >>>>> ******************************************************************= >>>>> * >>>>> =0D >>>>> >>>> >>>> -- >>>> Murray Eisenberg murray at math.umass.edu >>>> Mathematics & Statistics Dept. >>>> Lederle Graduate Research Tower phone 413 549-1020 (H) >>>> University of Massachusetts 413 545-2859 (W) >>>> 710 North Pleasant Street fax 413 545-1801 >>>> Amherst, MA 01003-9305 >>>> >>> >> >> >> >> ---------------------------------------------- >> Trying to argue with a politician is like lifting up the head of a >> corpse. >> (S. Lem: His Master Voice) >> >> >

**References**:**Re: Re: Re: RE: Re: Sometimes <space> means multiple***From:*János <janos.lobb@yale.edu>

**Re: Re: Re: Re: RE: Re: Sometimes <space> means multiple***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>