Coupled and tripled coincidence point results under ðF; gÞ-invariant sets in Gb-metric spaces and G-a-admissible mappings

In this paper, we prove that coupled and tripled coincidence point theorems under (F,g)-invariant sets for weakly contractive mappings defined on a G-metric space are immediate consequences of corresponding results via rectangular G-α-admissible mappings. This idea can also be applied to obtain coupled and tripled fixed point theorems in other spaces under various contractive conditions which reduces the proof considerably.