For example if i want to evaluate
Simplify[(a + b + c)/3 >= (a b c)^(1/3),
a > 0 && b > 0 && c > 0]
I must write the long expression
a > 0 && b > 0 && c > 0
Is there a shorter way to do that? I was thinking to define a domain but apparently it's not possible.
Subject (listing for 'short way of writing inequalities')