1. ## Notation question

Hi everyone,

I would like to state the following in a mathematical notation:

If x is greater than 0 somewhere between time t=0 and T, then event y occurs. Here is what I have in mind:

$x_t>0 \quad \forall \quad t \in T \quad \Rightarrow \quad \text{y event}$

Is that correct? I hope you have other suggestions, because I don't think the above is "state of the art" math notation.

Thanks a lot.

2. ## Re: Notation question

Hey neptunhiker.

You might try representing y as a function of time and x as a function of time for some region of time T.

If you define y(t) = 0 as no event occutring at time t and y(t) = 1 as an event occurring at time t, then you can say that

y(t) = H(x(t)) where H(t) = 0 if t <= 0 and H(t) = 1 if t > 0.

Then using this, you define y(t) as the condition of an event happening at time t which may be discrete or continuous.