*Annales de la faculté des sciences de Toulouse*(a set distance was introduced in a slightly different form in 1914 by Hausdorff, who credited Pompeiu's definition though), his contributions in complex analysis, including the areolar derivative [2] and the seminal Cauchy-Pompeiu's formula (higher dimensional analogues of the Cauchy-Pompeiu formula are topics of current research, while the formula was used in the theory of functions of several complex variables by Dolbeault and Grothendieck [5]), and for the celebrated Pompeiu's Conjecture that he formulated in his 1929 C. R. Acad. Sci. Paris article [4], a conjecture not fuly proved yet. Still, elegant analogues of Pompeiu's Conjecture continue to be proved in other areas [6] - this is an indicator of the fertility of the idea.

REFERENCES

[1] T. Bârsan and D. Tiba. One hundred years since the introduction of the set distance by Dimitrie Pompeiu. Institute of Mathematics of the Romanian Academy.

[2] D. Pompeiu. Sur une classe de fonctions d'une variable complexe. Rendiconti del Circolo Matematico di Palermo, t. XXXIII, Ist sem. 1912, pp. 108-113.

[3] Pompeiu's biography from the The MacTutor History of Mathematics archive.

[4] D. Pompeiu.

*Sur certains systèmes d'équations linéaires et sur une propriété intégrale des fonctions de plusieurs variables*, Comptes Rendus de l'Académie des Sciences Paris Série I. Mathématique, 188, 1138 –1139 (1929).

[5] R. Remmert. Theory of Complex Functions. Graduate Texts in Mathematics, Springer Verlag, 2nd Edition (1989).

[6] D. Zeilberger. Pompeiu's problem on Discrete Space. Proc. Natl. Acad. Sci. USA, Vol. 75 (8), 3555-3556 (1978).