Thread: quantifiers

Need help with
Express in quantiers:
The sequence {A n}n is element of natural numbers, is strictly decreasing
Give the negation of as well.
I am thinking for all N ,there exists x1 < x2, then f(x1) > f(x2) , kinda of lost...

Originally Posted by lukeheselden

Need help with
Express in quantiers:
The sequence {A n}n is element of natural numbers, is strictly decreasing
Give the negation of as well.

There are of course several different ways one might do this.
Here is one.

The negation is,

You mixed up the inequalities : the sequence is strictly decreasing ; what you wrote is for a strictly increasing sequence.

I assume it's a typo, but i point it out for the original poster not to confuse everything.

Originally Posted by pece

You mixed up the inequalities : the sequence is strictly decreasing ; what you wrote is for a strictly increasing sequence.

Good catch. I misread it.

thanks guys