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Hyperoperation Hierarchy

  1. Feb 16, 2015 #1
    I'm having some difficulty grasping the hierarchy of operations and the recurrent dynamics that characterize them, can anyone explain in layman's terms? (text rather than symbols is preferable as I want to learn theory intuitively)
  2. jcsd
  3. Feb 17, 2015 #2


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    So in other words, you want to have a more intuitive understanding of how tetration, pentation etc. is developed?

    I'm sure you probably find tetration (which we'll denote by a double up arrow, analogous to the single up arrow ^ used for exponentiation) to be easy to grasp, as a^^b is simply exponentiating b times (a power tower of a's that is b high, solved right to left, or at the top of the power tower then working downwards). The reason this is simple is because you already understand exponentiation. For a young student that only knows up to multiplication, it would be fairly simple for them to grasp the concept of exponentiation as a^b is the value a multiplied together b times, and similarly, for a student to learn multiplication, a*b is just a added together b times. Notice that with recursion, if you understand a certain level, then you can easily learn the next level.

    So the next step is pentation. Well obviously by recursion, a^^^b would be the value of a tetrated b times. But what does this mean? It's not as easy now because tetration isn't something that we've been exposed to very much, but we have shown that it is equivalent to saying how high the power tower should be. So then a^^^b is saying that we calculate a^^a (a tetrated a times) which gives us a new number (unfathomably large for a>3) and then we calculate a^^(a^^a) which is a stack of a's in a power tower that is a^^a high. Repeat this process until we've used up b amount of a's.

    Beyond this it gets even fuzzier. Intuitively understanding the next step gets farther out of reach, which is why we use mathematics. Recursive operations allow us to follow the pattern without having to know where we are exactly or where we're going to end up.
  4. Feb 17, 2015 #3
    much appreciated, i'll parse this and then familiarize myself with the symbolic denotations and directional associativity eventually, but wrapping my head around the infinite nature of the operative sequence (especially hypers n>4) is indeed 'brain-breaking' for me (as of yet) and zeration in particular perplexes me, but with such helpful replies^ the notions assimilate clearly.
  5. Feb 21, 2015 #4
    You could think of it this way:
    Let n = "rank" of operation, a = left operand, b = right operand

    operation(n, a, b) = operation(n-1, a, operation(a, n, b-1)
    operation(0, a, b) = b+1
    operation(n, a, 0) = a if n=0
    0 if n=1
    1 if n>1

    This notion of hyperoperations hold true no matter what n you plug in

    Ofc, a,b,n should be non negative integers
  6. Mar 1, 2015 #5
    Much appreciated.
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