Section NormedZmoduleTheory.
Variable V : normedZmodType R.
Implicit Types (u v w : V).
Hint Resolve normr_real : core.
Arguments real_ler_normlP {x y}.
Definition real_lter_norml := (real_ler_norml, real_ltr_norml).
Arguments real_ltr_normlP {x y}.
Definition real_lter_normr := (real_ler_normr, real_ltr_normr).

Lemma leif_0_sum (I : finType) (P C : pred I) (E : I -> R) :
(forall i, P i -> 0 <= E i ?= iff C i) ->
0 <= \sum_(i | P i) E i ?= iff [forall (i | P i), C i].