Poweroids
#3
(12/18/2009, 08:13 AM)andydude Wrote:
  • \( (\mathbb{R}^{+}-\{1\},\ \mathbb{R}^{+},\ \uparrow,\ 1) \) forms a poweroid.
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Andrew Robbins

SCRATCH THAT! it is false.

\( \{1/2,\ 2\} \subset \mathbb{R}^{+}-\{1\} \), but \( \log_2(1/2) = -1 \) which is not a member of the positive reals. However, with the slight modification
  • \( (\mathbb{R}^{+}-\{1\},\ \mathbb{R}-\{0\},\ \uparrow,\ 1) \) forms a poweroid.
I believe the statement is true.

The reason why 0 and 1 must be excluded is so that \( \sqrt[y]{x} \) is uniquely defined. If we include 1, 0 in the base domain, exponent domain respectively, then roots are not uniquely defined, at which point it stops being a poweroid.
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Messages In This Thread
Poweroids - by andydude - 12/18/2009, 08:13 AM
RE: Poweroids - by andydude - 12/19/2009, 10:55 PM
RE: Poweroids - by andydude - 12/19/2009, 11:01 PM



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