The equivalent properties of transforms of L-IFS to Z-fuzzy sets (FS), interval value IFS to L-FS, interval value (IV) FS to IFS, and IFS to IV IFS are proved by means of D-K operators.

• 证明了L-IFS到L-模糊集,区间值IFS到L-模糊集,区间值模糊集到IFS,IFS到区间值IFS之间变换的等价性。