View source for Frobenius theorem on Pfaffian systems

A theorem on the conditions for a system of [[Pfaffian equation]]s 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|foliation]]. For several equivalent formulations of the Frobenius theorem, see the articles [[Involutive distribution]]; [[Cauchy problem]]; for a version with minimum differentiability requirements see [[#References|[2]]]. The name of the theorem is connected with the account of it in [[#References|[1]]], but does not accord with the information given there about its history.

====References====
<table>
<TR><TD valign="top">[1]</TD> <TD valign="top"> G. Frobenius, "Ueber das Pfaffsche Problem" ''J. Reine Angew. Math.'' , '''82''' (1877) pp. 230–315</TD></TR>
<TR><TD valign="top">[2]</TD> <TD valign="top"> P. Hartman, "Ordinary differential equations" , Birkhäuser (1982) {{MR|0658490}} {{ZBL|0476.34002}} </TD></TR>
</table>



====Comments====
G. Frobenius actually also treats the [[normal form]] of a [[differential form]] of degree 1.

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