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Am 09.03.2025 um 00:26 schrieb efji:I just pointed out the fact that the notation x^n is never used in the case of non associative operators because it is ambiguous without further definition. Think about the vector product in R^3 for example, which is not associative, and not commutative too. Nobody would write x^3 for (x \wedge x)\wedge x.Le 08/03/2025 à 23:55, Moebius a écrit :Might be the case, yes. So what? :-PAm 08.03.2025 um 23:47 schrieb Moebius:>Am 08.03.2025 um 14:32 schrieb efji:>Le 08/03/2025 à 14:18, Richard Hachel a écrit :>Associativity is MANDATORY to be able to write something like i^4 = i*i*i*i.>
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For a non associative operator, i^4 means NOTHING.
Oh, i^(n+1) just might mean (i^n) * i (with n e IN).
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[And i^0 = 1.]
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Then: i^4 = ((i*i)*i)*i.
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[Hint: recursive definition:
x^0 = 1
x^(n+1) = x^n * x (for all n e IN)]
x^0 = 1
x^(n+1) = (x^n) * x (for all n e IN)]
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... if you like.
I don't like.
What if * is not commutative ?
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(x^n) * x =/= x * (x^n)
But -hint- you talked about *associativity*, not about *commutativity*. :-)
Trying to use crank strategies?fighting fire with fire :)
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