Arguments fixedSpaceP {K vT f a}.
Arguments fixedSpacesP {K vT f U}.
Section LinAut.
Variables (K : fieldType) (vT : vectType K) (f : 'End(vT)).
Hypothesis kerf0 : lker f == 0%VS.

Lemma limg_comp f g U : ((g \o f) @: U = g @: (f @: U))%VS.
End LinearImageComp.