Abbreviating First Order Logic With Identity and Membership
in [Logic]
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From: Tim Little on 27 Apr 2010 22:39 On 2010-04-27, MoeBlee <jazzmobe(a)hotmail.com> wrote: > Oops, sorry, to be fair, you did just mention that you're not > proposing a rigorous syntax but rather informal notational > conventions. Actually in the first post he *did* say that it was proposed as an alternative for the current notation as a rigorous formal notation. - Tim
From: Tim Little on 27 Apr 2010 22:44 On 2010-04-27, zuhair <zaljohar(a)gmail.com> wrote: > So for example instead of writing > > F(x0,...,xn) one may write F(x0...xn) So how would you write F(A|B,C)? - Tim
From: Tim Little on 27 Apr 2010 22:54 On 2010-04-27, zuhair <zaljohar(a)gmail.com> wrote: > On Apr 27, 3:27 am, William Elliot <ma...(a)rdrop.remove.com> wrote: >> For example, parse: A BvC v D E Note: under some circumstances, Google mangles successive spaces in quoted text. Just by itself, that makes it a terrible idea to use variable-width spacing to structure logical formulas in this newsgroup, especially by people such as zuhair who post via Google. > However I think this must be written in a clearer manner like: > > A B|C | D E You seriously believe this is both more concise and clearer than a fairly standard (A(B+C)+D)E? It most certainly is not more concise: your rendition uses 17 characters, the standard one uses 11. In my opinion it is also less clear, leaving absolutely no reason to use it whatsoever. - Tim
From: Tim Little on 27 Apr 2010 23:02 On 2010-04-27, Phil Carmody <thefatphil_demunged(a)yahoo.co.uk> wrote: > Anyone who relies on whitespace to carry essential information > is living in a state of ignorance about how lossy communication is. Yes, and it is especially rich coming from one posting via Google, one of the worst offenders for mangling spacing in Usenet posts. - Tim
From: William Elliot on 27 Apr 2010 23:50
On Tue, 27 Apr 2010, zuhair wrote: > On Apr 27, 3:55�am, Phil Carmody <thefatphil_demun...(a)yahoo.co.uk> > wrote: >> Far easier to just use RPN: >> Anyone who relies on whitespace to carry essential information >> is living in a state of ignorance about how lossy communication is. > > You can if the formula is not long enough, and not so complex. > With Polish notation, spaces can be very useful to make long formulas easy to read by depicting the phrasing. For example: C CNqNp Cpq C CpCqr CCpqCpr Or with the convention that periods are like spaces, to be ignored, C CpCpq C.Cpq.Cpr With the dot convention p ->. q -> r :->: p -> q .->. p -> r p ->. q->r :->: p->q .->. p->r With the left parathesis convention p -> (q -> r) -> (p -> q -> (p -> r)) p -> (q->r) -> (p->q -> (p->r)) p -> f -> f -> p > as I say any formula which is long or complex such as to defy this > methodology > then to avoid any possible confusion one must break it down to > component formula. Anyway these complex long formulas would be > incomprehensible > to the human reader if they are presented in one block. > > Zuhair >> -- >> I find the easiest thing to do is to k/f myself and just troll away >> -- David Melville on r.a.s.f1 > > |