Let(E′αλ,f′αβμλ)be another inverse system of sets relative toI×L, and for each(α,λ)∈I×Lletuαλbe a mapping ofEαλintoE′αλsuch that theuαλform an inverse system of mappings. Then
(17)α,λlimuαλ=λlim(αlimuαλ).
The verification is similar to that of Proposition 4.
Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.