Frobenius theorem on Pfaffian systems

A theorem on the conditions for a system of Pfaffian equations to be completely integrable, or (in geometrical terms) on conditions under which a given field of $n$-dimensional tangent subspaces on a differentiable manifold is the tangent field of some foliation. For several equivalent formulations of the Frobenius theorem, see the articles Involutive distribution; Cauchy problem; for a version with minimum differentiability requirements see [2]. The name of the theorem is connected with the account of it in [1], but does not accord with the information given there about its history.

References

[1]	G. Frobenius, "Ueber das Pfaffsche Problem" J. Reine Angew. Math. , 82 (1877) pp. 230–315
[2]	P. Hartman, "Ordinary differential equations" , Birkhäuser (1982) MR0658490 Zbl 0476.34002

Comments

G. Frobenius actually also treats the normal form of a differential form of degree 1.