Section Angles_5.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma anga_not_lg_null : forall a la lc A B C, Q_Cong la -> Q_Cong lc ->
Q_CongA_Acute a -> la A B -> lc C B -> a A B C -> ~ Q_Cong_Null la /\ ~ Q_Cong_Null lc.