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**Per** I have had problems trying to prove that one inequality does not imply another inequality. Let ε, λ, X and Y be scalars where

ε ≥ 0

λ > 0

-∞ < X < +∞

-∞ < Y < +∞

We have the following two inequalities:

INEQUALITY 1:

X – Y ≥ ε λ

INEQUALITY 2:

if ε = 0 then X – Y ≥ 0

if ε > 0 then X – Y > 0

I want to show that INEQUALITY 1 implies INEQUALITY 2, but that the converse is not true. That is,

i) If INEQUALITY 1 is satisfied then INEQUALITY 2 must be satisfied

ii) If INEQUALITY 2 is satisfied then INEQUALITY 1 need not be satisfied

While i) is easy to prove, I have gotten stuck on trying to prove ii). The thing is that I need to show it in the general case, and not with a specific example using made up numbers.

Not at all! To show something general is not true it is enough ONE single counterexample...for example, $\displaystyle X=2\,,\,Y=1\,,\,\epsilon=3\,,\,\lambda=45$

Tonio

I would be very grateful for all help I can get!!