Definisable haefliger's type theorem

Let A be an o-minimal expansion of the real feld, M a submanifold of R ⁿ and ω a differentiable 1-form on M. We assume that M and ω are definable in A and ω defines a foliation on M of codimension one. Then there are definable, open subsets Mi of M, for i = 1, ..., r, such that every C¹ loop contained in Mi is tangent to ker(ω) at some point. © Astérisque 323, SMF 2009.