Unlesss

1990, James Glimm, The Legacy of John Von Neumann, American Mathematical Society, →ISBN, page 279, Partial Order: G ≥ H unlesss (unless and only unless) H ≥ some Gᴿ or some Hᴸ ≥ G.

Source: wiktionary

A subset S is called absorbing if to each x#92;inX there is a real number #92;epsilon#61;#92;epsilon#95;xgt;0 such that #92;lambdax#92;inS for all #92;lambda with 0lt;#92;left#124;#92;lambda#92;right#124;#92;le#92;epsilon. Trivially the set X is absorbing; on the other hand #92;#123;0#92;#125; can never be absorbing (unlesss X#61;#92;#123;0#92;#125;).

Source: wiktionary

2004, William Fraser, Susan Hirshberg, and David Wolfe, "The Structure of the Distributive Lattice of Games Born by Day n", in Integers: Electronic Journal of Combinatorial Number Theory 5(2) (2005), page 2, G ≥ H unlesss H ≥ Gᴿ or Hᴸ ≥ G for some Gᴿ ∈ Gᴿ or some Hᴸ ∈ Hᴸ. ¶ (Analogous to “iff”, the term “unlesss” means “unless and only unless”.)

Source: wiktionary