Natural negation of interval-valued t-(co) norms and implications

In this paper, we investigate interval-valued fuzzy negations induced by interval-valued t -norms, t -conorms or implications. Some properties of interval-valued fuzzy negations induced by interval-valued sup-morphism t -norms, inf-morphism t -conorms or R -implications are firstly obtained. We also show interval-valued automorphisms acting on the interval-valued fuzzy negations induced by interval-valued t -norms, t -conorms or implications. Finally, the relations among the interval-valued fuzzy negations induced by interval-valued t -norms, t -conorms or implications are explored.