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Proof Introduction

  1. Jun 16, 2005 #1

    Does anybody have any advice on writing definitions for a scientific proof?
  2. jcsd
  3. Jun 16, 2005 #2

    matt grime

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    definitions are given, you deduce things from them. the only advice you need is to do some, practice them, and read a lot of examples.
  4. Jun 16, 2005 #3
    "define x as ..."
    "let y be ..." ??
    "denote x ..."
  5. Jun 16, 2005 #4


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    definitions should be reserved for concepts that are found to be important, even central.
  6. Jun 16, 2005 #5
    How can one tell when the definitions are in conjunction with the hypotheses?
  7. Jun 17, 2005 #6
    There is no such thing as a scientific proof. I suppose you mean mathematical or logical proof.
  8. Jun 17, 2005 #7

    matt grime

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    by reading them and thinking (though i am guessing what you mean by conjunction)
  9. Jun 17, 2005 #8


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    The definitions have to be very well stated so there is no fuzzyness in what they connote. This is called well-defined. One of the best ways to get well-defined objects in mathematics is with axioms. You set up a small number of statements, called axioms, describing the thing you want to prove theorems about, and then you prove two special theorems:
    1. The axioms don't contradict each other. (Consistency)
    2. There actually is something that the axioms describe (Existence)

    If you can do that, the object is well-defined, and you can make theorems about it by referrring to the axioms. By view of your consistency proof, this won't lead you to contradictions, and by view of the existence proof, you won't be talking about nothing at all.
  10. Jun 17, 2005 #9
    If I were to use Newton's work on Principa as a example. He used 8 definitions before he wrote his 3 axioms or laws of motion. Now I have written an equation on a natural phenomenon and I am wondering what parts I should define before I start writing the axioms. Actually I already started writing the axioms but I feel like I am ahead of myself. Because I think the definition will give the proof a clear understanding of the natural phenomenon.
  11. Jun 17, 2005 #10
    well then just write the definition as "x is position" etc.
    or the set A = {...|... }
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