Section InertiaDprod.
Variables (gT : finGroupType) (G K H : {group gT}).
Implicit Type L : {group gT}.
Hypothesis KxH : K \x H = G.

Lemma cfConjgBigdprod phi :
(cfBigdprod defG phi ^ y = cfBigdprod defG (fun i => phi i ^ y))%CF.