I'm trying to figure out the correct notation for this situation for use in Machine Learning.
I have various ratings (for texts):
t1 ratings = +2, +3, +4
t2 ratnigs = -1, -2, +4
If when you multiply the minimum by the maximum of each vector you get a negative number, then the function output should be true. I guess each vector should be called y as they are the ratings for the Machine Learning.
This is as close as I have got, but I don't know if it's acceptable: $$ f(y_t )=\min(y_t )\times\max(y_t )<0 $$
That is, for the vector or set of ratings y for a text t,the result should be TRUE if the minimum value in the set multiplied by the maximum value in the set is negative.