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Homework Help: Negating a statement need help ly!

  1. Apr 13, 2012 #1
    negating a statement...need help urgently!

    Hi everyone:

    I am not sure about the following thing I did. Let J be a countable finite set, and [itex]f_{jk}^{0}[/itex] and [itex]f_{jk}^{1}[/itex] be two continuous functions defined on [0,1]. Consider the following statement:

    [itex] \forall lj\in J,\forall x\in[0,1],\: \, f_{jk}^{0}(x)\leq f_{jk}^{1}(x)[/itex]

    Negating the above statement gives me:

    [itex] \exists lj\in J,\exists \hat{x} \in[0,1],\: \, f_{jk}^{0}(\hat{x})> f_{jk} ^{1}(\hat{x})[/itex]

    Question 1: Am I correct in the way I negate the original statement?

    Question 2 (and perhaps the most important): The fact that the negation involves only one member gives the freedom to assume that every other element satisfies the properties in the original statement? i.e., can I assume, while constructing a proof, that [itex] \forall hz\in J[/itex] other than l and j, [itex] f_{lz}^{0}(x)\leq f_{lz}^{1}(x)\: \forall x\in[0,1][/itex]?

    Thanks a lot! I truly appreciate any help you can give me!
  2. jcsd
  3. Apr 14, 2012 #2
    Re: negating a statement...need help urgently!

    any one out there willing to help?
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