Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

Lemma lemma_fiveline :
forall A B C D a b c d,
Col A B C -> Cong A B a b -> Cong B C b c -> Cong A D a d -> Cong C D c d -> Cong A C a c -> neq A C ->
Cong B D b d.