Re: Fortran or Ada?

[Terry Devine <tdevine@mitre.org>]

Daniel Barker wrote:
> 
> `In the language of everyday life it very often happens that the same word
> signifies in two different ways - and therefore belongs to two different
> symbols - or that two words, which signify in different ways, are
> apparently applied in the same way in the proposition.
> 
> `Thus the word "is" appears as the copula, as the sign of equality, and as
> the expression of existence; "to exist" as an intransitive verb like "to
> go"; "identical" as an adjective; we speak of SOMETHING but also of the
> fact of SOMETHING happening.

"That depends on what the definition of "is" is."
-- William Jefferson Clinton

> 
> `(In the proposition "Green is green" - where the first word is a proper
> name and the last an adjective - these words have not merely different
> meanings but they are DIFFERENT SYMBOLS.)
> 
> `Thus there easily arise the most fundamental confusions (of which the
> whole of philosophy is full).
> 
> `In order to avoid these errors, we must employ a symbolism which excludes
> them, by not applying the same sign in different symbols and by not
> applying signs in the same way which signify in different ways. A
> symbolism, that is to say, which obeys the rules of LOGICAL grammar - of
> logical syntax.
> 
> `(The logical symbolism of Frege and Russell is such a language, which,
> however, does still not exclude all errors.)
> 
> `In order to recognize the symbol in the sign we must consider the
> significant use.
> 
> `The sign determines a logical form only together with its logical
> syntactic application.
> 
> `If a sign is NOT NECESSARY then it is meaningless. That is the meaning of
> Occam's razor.'
> 
> - Wittgenstein, Tractatus Logico-Philosophicus, propositions 3.323-3.328.
> 
> (Capitals used in place of italics. Translation is the original 1922
> version, by Ogden, which had Wittgenstein's approval. Published in London
> & New York by by Routledge; reprinted 1996.)
> 
> If I may veer into another language, C - and thus justify adding another
> news group to the `to' line -
> 
> #include <stdio.h>
> main()
> {
>   int a[100];         /* `a' means array */
>   printf("%p\n", a);  /* `a' means pointer */
>   a = a + 1;          /* ILLEGAL, since `a' means array again */
> }
> 
> `a' here means two different things:
> 
> (1) an array of 100 normal-width integers;
> (2) a pointer to a normal-width integer (in fact, to the first integer in
> an array of 100 such).
> 
> To say that, in the call to printf(), the first thing is implicitly
> converted to the second thing is to linguistically `work around' the basic
> problem, that `a' has two meanings. Meaning (2) can also be expressed as
> 
> &a[0]
> 
> So, the example reveals two faults in the C language. Namely, that `a', as
> a local variable in one function, can have two meanings; and also that one
> of these meanings is may be expressed by either of two symbols. This is a
> crying shame! Why does `a' have two meanings, when, given the possibility
> of `&a[0]', one would have sufficed without reducing the functionality of
> the language?
> 
> The answer is historical, as revealed by an interesting paper, "The
> Development of the C Language" by Dennis Ritchie, available from Dennis
> Ritchie's home page, http://plan9.bell-labs.com/cm/cs/who/dmr/index.html.
> 
> Daniel Barker,
> Institute of Cell and Molecular Biology,
> Swann Building,
> King's Buildings,
> Mayfield Road,
> Edinburgh
> EH9 3JR
> UK