Section CfDotOrthonormal.
Variables (M : {group gT}) (S : seq 'CF(G)) (nu : 'CF(G) -> 'CF(M)).
Hypotheses (Inu : {in 'Z[S] &, isometry nu}) (onS : orthonormal S).
Let oSS := orthonormal_orthogonal onS.
Let freeS := orthogonal_free oSS.
Let nS1 : {in S, forall phi, '[phi] = 1}.
End CfDotOrthonormal.

Lemma zchar_small_norm phi n :
phi \in 'Z[irr G] -> '[phi] = n%:R -> (n < 4)%N ->
{S : n.-tuple 'CF(G) |
[/\ orthonormal S, {subset S <= 'Z[irr G]} & phi = \sum_(xi <- S) xi]}.