End ConsttIndExtendible.

(* This is Isaacs, Corollary (6.19). *)
Corollary cfRes_prime_irr_cases G N s p (chi := 'chi[G]_s) :
N <| G -> #|G : N| = p -> prime p ->
[\/ 'Res[N] chi \in irr N
|  exists2 c, injective c & 'Res[N] chi = \sum_(i < p) 'chi_(c i)].