On the existence of coincidence and common fixed point of two rational   type contractions and an application in dynamical programming
  In this work, we establish some coincidence point results for self-mappings satisfying rational type contractions in generalized metric spaces in the sense of Branciari [7]. Presented coincidence point theorems weak and extend numerous existing theorems in the literature besides furnishing some illustrative examples for our results. Finally, our results applies, in particular, to the study of solvability of functional equations arising in dynamic programming. 
Ahmed H. Solimana, Tamer Nabil
math.FA