We prove that for a finite collection of sets definable in an o-minimal structure there exists a compatible definable stratification such that for any stratum the fibers of its projection onto satisfy the Whitney property with exponent 1.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-ap92-2-4, author = {Beata Kocel-Cynk}, title = {Definable stratification satisfying the Whitney property with exponent 1}, journal = {Annales Polonici Mathematici}, volume = {92}, year = {2007}, pages = {155-162}, zbl = {1146.14031}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap92-2-4} }
Beata Kocel-Cynk. Definable stratification satisfying the Whitney property with exponent 1. Annales Polonici Mathematici, Tome 92 (2007) pp. 155-162. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-ap92-2-4/