# Pentation - The Best From Greece     Book Hotels in Pentation

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### Source: WikiPedia

Description:
Pentation is the operation of repeated tetration, just as tetration is the operation of repeated exponentation and is a hyperoperation. Like tetration, it has little real-world applications. It is non-commutative, and therefore has two inverse functions, which might be named the penta-root and the penta-logarithm (analogous to the two inverse functions for exponentiation: nth root function and logarithm). Pentation also bounds the elementary recursive functions[citation needed].

The word "Pentation" was coined by Reuben Goodstein from the roots penta- (five) and iteration). It is part of his general naming scheme for hyperoperations.

Pentation can be written in Knuth's up-arrow notation as or .

It is not known how to extend pentation to complex or non-integer values.[citation needed]

Using super-logarithm‎s, can be done when b is negative or 0, provided it is not too negative. For all positive integer values of a negative pentation is as follows:

Any other case of this type of pentation produces an undefined result, since integer tetration does not take on the value -1.

It can also be done when a is negative, but this is only the case when a is equal to -1. For all positive integer values of b, the three possible answers that you can get for are shown below:

If , is undefined because tetration is only defined for b greater than -2, while if a is zero, we obtain the presumably-indeterminate form .

As its base operation (tetration) has not been extended to non-integer heights, pentation is currently only defined for integer values of a and b where a > 0 and b ≥ 0, and a few other integer values which may be uniquely defined. Like all other hyperoperations of order 3 (exponentiation) and higher, pentation has the following trivial cases (identities) which holds for all values of a and b within its domain:

Other than the trivial cases shown above, pentation generates extremely large numbers very quickly such that there are only a few non-trivial cases that produce numbers that can be written in conventional notation, as illustrated below:  Pentation  mimetex cgi 5^ 5^ 5 4e2a561a3d15ce063129e8200cfeb192 png bd6e935aaf25f4af41003727c4b720af png 1328649 7 png 1328649 6 png SMN JANCEG gif    