Bounded Quantification: Full F<: intuition
Consider these assertions:


all the cats in my house are grey
all the cats in my town are grey


The second assertion implies the first, since any cat in my house is also in my town, so by the assertion it must be grey. In other words, "cats in my town" is a superset of "cats in my house", so the second assertion is stronger (it applies to more cats).

In the same way, the type S = ∀X&lt;:S1.T2 is stronger than T = ∀X&lt;:T1.T2 since S1 is a supertype of T1. A program of type S must work in all cases (types X) where a program of type T would work, and possibly even more cases.