L’Oreal applied for a patent on a sun protection factor (SPF) product in Luxembourg on April 13, 1987. It applied in the U.S. on April 12, 1988.

Estee Lauder applied for a patent in the U.S. on the same SPF on December 21, 1987. Assuming that the Paris Convention and Patent Cooperation Treaty applied, who is entitled to the U.S. patent?

Estee Lauder Inc. v. L’Oreal, S.A., 129 F.3d 588

(Fed. Cir. 1997).