I'm stuck in a notation problem which I cannot clarify: I have a text which says : $x = \text{some constant}* Z\left(\frac{[S(t)-S(t-1)]}{\text{standard deviation of S}}\right)$ with $Z$ standard normal distribution. Now my question is: how should I interpret that $Z(\text{something})$? I don't have any other information about this formula and I don't understand when it says $Z$(one variable).
edit to be more clear: I don't understand what is $Z$(one variable) is the z-score associated to that variable? is the standard normal distribution associated to that variable? don't think it's the second since should have 2 parameters is it the cdf of the standard normal distribution for that variable and it's the same as writing $P(X < \text{one variable}) =$?
Thanks.