When is the operation $\ddot{I}{„}_{T,L}$ a triangle function on $\Del^+$?

Hongliang Lai, Mengyu Luo, Jie Zhang

This paper resolves an open problem posed by Schweizer and Sklar in 1983. We establish that the binary operation $\tauTL$ is a triangle function on $\Delp$ if and only if the follo…