Variables

[R. C. James Harlow]

On Sunday 24 April 2005 03:20, Richard Blackwood wrote:
> To All:
>
>     Folks, I need your help. I have a friend who claims that if I write:
>
> foo = 5
>
> then foo is NOT a variable, necessarily. 

  This is a really amusingly recursive discussion. Your friend has a piece of 
knowledge, "what a variable is and is not". He uses the word "variable" to 
refer to this piece of knowledge. Now, if in some parallel universe people 
used the word "hairbrush" to refer to this bit of knowledge, that wouldn't 
stop his argument having validity if he travelled to that universe - if it 
would then it's already invalidated, as there are more people in *this* 
universe who use the word variable to refer to foo than there are who insist 
that it's not correct, by a significant proportion. So by corollary your 
friend has already argued that one can use many different words to correctly 
refer to the same concept.

  I think your friend would also find it hard to disagree that a single word 
can have multiple meanings, like the example given of "Domain" in maths. I 
think he would have a similarly tough time saying that these words with 
multiple meanings were only allowable in maths, not in english or the 
offshoots of maths like programming. So there's no reason why the concept of 
what you call a variable and what he calls a variable shouldn't be different.

  In summary, the words he uses to describe variables are constants, but point 
at variables, which are different than the constants you use to describe 
variables, which point at variables, and vary from the variables that his 
variables point at.

  And if that last sentence doesn't convince him of the futility of trying to 
use natual language to communicate precise concepts, nothing will.


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