Possibly this is not tractable for your example. But it won't work for anyone if the code is not made available.
It depends on how complicated your function is. For example
function = a + b - c; Reduce[function > 0 && And[a > 0, b > 0, c > 0, d > 0, e > 0, f > 0, 1 >= g >= -1, 1 >= h >= -1]]
Please provide full details and code about your problem to make it easier for other members to help you.
The function is very complicated. It does not work for me.
