Section MoreIntegralChar.
Implicit Type gT : finGroupType.

(* This is Burnside's vanishing theorem (Isaacs, Theorem (3.15)). *)
Theorem nonlinear_irr_vanish gT (G : {group gT}) i :
'chi[G]_i 1%g > 1 -> exists2 x, x \in G & 'chi_i x = 0.