RE: [R] a < b < c is alway TRUE

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From: Philippe Grosjean (phgrosje@ulb.ac.be)
Date: Fri 06 Jul 2001 - 21:24:38 EST 

Message-id: <MABBLJDICACNFOLGIHJOCEFICEAA.phgrosje@ulb.ac.be>

>One of our students did something like:

> x[a < b < c]

>instead of

> x[a < b & b < c]

>But why is

> 3 < 2 < 1 # [1] TRUE ???

>Is there any reason?
>Or wouldn't it be better to get a warning / error?

>Uwe Ligges

The answer is simple: the first inequation 3 < 2 is solved, which gives
FALSE. Then the second inequation to be solved is: FALSE < 1. Since
as.numeric(FALSE) is 0, you have to solve 0 < 1, which is... TRUE. Hence,
this is not a bug, but an incorrect use of the R language.
Best regards,

Philippe Grosjean

...........]<(({?<...............<?}))><...............................
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