Proposition 4. If X is an almost-complex submanifold in compatible (M, ω, J), then X is symplectic (i.e. ω| X is nondegenerate). Proof. ∀u ∈ T xX, u = 0,Ju ∈ T xX and ω(u, Ju) > 0, so ∀u ∈ T xX {0},ω(u, ·)| T xX ∈ T x ∗X is nonzero, giving us an isomorphism TX → …