Rotation-invariant t-norms: Where triple rotation and rotation–annihilation meet

Generalizing the notion of a zoom of a t-norm not only allows to extend the triple rotation method and its corresponding decomposition, but also allows to describe the interface between the triple rotation method and the rotation(-annihilation) method. An alternative view on the partition behind the rotation(-annihilation) method is required to make both methods compatible. Besides zooms we also use contour lines and the companion of a t-norm to concisely formulate the results.