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Interval FAQ:
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About Sun's f95 with Interval Support
# Interval FAQ

Examples of interval arithmetic -- Is [A] - [A] = 0?

## Examples of Interval Arithmetic

**For interval numbers A = [1, 2], B = [1, 2]
**

A - A = 0?

Response by R. Baker Kearfott:

It depends on how you interpret the above. If interval arithmetic
is meant to give bounds on the range, then you can simplify the
expression symbolically to 0. However, if the subtraction is
done using the basic rules of interval arithmetic, then A-A gives
the same result as A-B, leading to the well-known phenomenon of
"overestimation"

**A - B = [-1, 1]?**

Response by R. Baker Kearfott:

Yes

**A / A = 1?**

Response by R. Baker Kearfott:

See my comments about A-A.

**A / B = [0.5, 2]?**

Response by R. Baker Kearfott:

YEs

**For interval numbers A = [1, 2], B = [1, 2]
**

A - A = 0?

Response by R. Baker Kearfott:

Baker

[ Marquette
| MSCS
| Corliss
| Vladik's Intervals
]

Interval FAQ:
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About Sun's f95 with Interval Support
If *you* have a question related to validated computing, interval
analysis, or related matters, I recommend

This page URL:
http://www.mscs.mu.edu/~georgec/IFAQ/what_is1.html

Last modified November 1, 19100.
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