Address.
Mendel University, Department
  of Mathematics,
  Zemedelska 3, 613 00 Brno, Czech Republic
E-mail. marik@mendelu.cz
Abstract.
In the paper the discrete version of the Morse's singularity
  condition is established. This condition ensures that the discrete
  functional over the unbounded interval is positive semidefinite on
  the class of the admissible functions. Two types of admissibility
  are considered.
AMSclassification. 39A12.
Keywords. Difference equation, half-linear equation, functional, singular functional.