A Reeb component is a Reeb foliation 
whose leaves are proper. A foliation which has
no Reeb components is said to be Reebless.
Reeb Component
See also
Foliation, Foliation Leaf, Generalized Reeb Component, Reeb Foliation,This entry contributed by Christopher Stover
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References
Imanishi, H. and Yagi, K. "On Reeb Components." J. Math. Kyoto Univ. 16, 313-324, 1976.Cite this as:
Stover, Christopher. "Reeb Component." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/ReebComponent.html