Global Minimum (or absolute minimum)
Given
x ∈ Rn
x is minimum global if
∀ y ∈ Rn ∩ S => f(x) ≤ f(y)
Note1: Similarly we can define the strict global minimum if the inequality we substitute f(y) < f(x).
Note2: Similarly we define the maximum Global if we substitute the less-equal to greater-equal.