Interval-Valued Neutrosophic Oversets, Neutrosophic Undersets, and Neutrosophic Offsets

Florentin Smarandache
2016 International Journal of Science and Engineering Investigations   unpublished
We have proposed since 1995 the existence of degrees of membership of an element with respect to a neutrosophic set to also be partially or totally above 1 (over-membership), and partially or totally below 0 (under-membership) in order to better describe our world problems [published in 2007].