Triangular-norm-base addition of fuzzy intervals on the extended real
line is reduced to the addition of shapes on [0, infinity]. The additi
on of fuzzy intervals, including LR-fuzzy intervals, LR-fuzzy numbers,
LT-and TR-fuzzy numbers, based on limit t-norms is recalled. For cont
inuous Archimedean t-norms, special types of incoming summands allowin
g the exact output computation are introduced. Several examples are gi
ven. (C) 1997 Elsevier Science B.V.