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Re: inch to cm was Re: WD-CSS21-20020802 section 4, "CSS 2.1 syntax and basic data types",

From: Liorean <Liorean@user.bip.net>
Date: Sat, 16 Nov 2002 02:27:38 +0100
Message-Id: <5.1.0.14.0.20021116021508.00ace848@pop3.bip.net>
To: natej@excite.co.jp, www-style@w3.org, Bert Bos <bert@w3.org>
Cc: Boris Zbarsky <bzbarsky@MIT.EDU>

At 18:52 2002-11-15 +0900, natej@excite.co.jp wrote:
>>How does this limit precision? An inch (in the real world) is defined to 
>>be precisely 25.4 mm (or 2.54 cm).
>and a foot is equal to 30cm or 300mm.

I've never seen any definition of foot as 300mm - I've seen 30cm though. In 
fact, most of my math books conversion tables list foot as 3.04810^-1 m. 
That rounds to 30 cm though, but never to 300mm.

>a foot is equal to 12 inches. an inch is 2.54cm. a foot is 30.48cm, ergo 
>30cm "is equal to" 30.48cm.

"30 cm", in reality, corresponds to the interval 29.5<=x<30.5, in which you 
can find the value 30.48cm. In fact, there is nothing that tells us that 
the zero is significant, in other words, if you want to be picky, 30 cm 
corresponds to the interval 25<=x<35.

>at least insert the word "approximately" between "is" and "equal."

An inch is defined as 25.4mm. Period. A foot is defined as 12 inches or 
304.8mm.

// Liorean
Received on Friday, 15 November 2002 20:27:44 GMT

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