... notice below). For information about publishing your research in Fixed Point Theory and Applications go to http://www.fixedpointtheoryandapplications.com/authors/instructions/ For information about ... Principles of weakly contractive maps in Hilbertspaces. In: New Results in Operator Theory and its Applications, Gohberg, I, Lyu-bich, Y (eds.), vol. 98 of Operator Theory: Advances and Applications. ... ϕλ(dλ(gx, gy)) (12) for all λ ∈ A, for all x, y ∈ X for which gx gy. If there exists x0such that gx0 fx0,then f and g have a coincidence point.Proof. Following the proof of Theorem 3.1,...