Institute of Mathematics and Informatics Bulgarian Academy of Sciences
Serdica Mathematical Journal, Vol. 22, No 3, (1996), 341p-358p
The definition of the weak slope of continuous functions introduced by
Degiovanni and Marzocchi (cf. ) and its interrelation with the notion “steepness”
of locally Lipschitz functions are discussed. A deformation lemma and a mountain
pass theorem for usco mappings are proved. The relation between these results
and the respective ones for lower semicontinuous functions (cf. ) is considered.
∗Partially supported by Grant MM 409/94 of the Mininstry of Education, Science and Technology,
∗∗Partially supported by Grants MM 521/95, MM 442/94 of the Mininstry of Education, Science
and Technology, Bulgaria.