If g∈G, the transform of Dt under g is Dεg∗t∗εg−1.
The value of this transform at gx is
τ(g)∗(Dt(x))=τ(g)∗(t∗εx)=εg∗(t∗εx)(Proposition 14 (i))=(εg∗t∗εg−1)∗εgx(Propositions 1 and 2)=Dεg∗t∗εg−1(gx).
Let (x,g)↦μ(x,g)=xg be a law of right operation of class C′ of G on X. Let s≤r and t∈Us(G). For all x∈X, εx∗t∈Tx(s)(X). The mapping x↦εx∗t is called the field of distributions defined by t and the action of G on X and is sometimes denoted by Dtu or simply Dt. Let Ω be an open subset of X. If f:Ω→F is of class C′, the function f∗t∨ is denoted by Dtf. Then
(Dtf)(x)=⟨εx∗t,f⟩
and, in the obvious notation,
Dt∗t′f=Dt(Dt′f)
Dt∗t′=Dt∘Dt′.
Proposition 21 remains valid. Let g∈G. The transform of Dt under g (that is under the automorphism x↦xg of X) is Dεg−1∗t∗εg.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.
Nothing.