scheme :: QUANTAL1:sch 3
LUBFraenkelDistr{ F₁() -> non empty Lattice-like complete QuantaleStr , F₂( set , set ) -> Element of F₁(), F₃() -> set , F₄() -> set } :

"\/" ( { ("\/" ( { F₂(a,b) where b is Element of F₁() : b in F₄() } ,F₁())) where a is Element of F₁() : a in F₃() } ,F₁()) = "\/" ( { F₂(a,b) where a, b is Element of F₁() : ( a in F₃() & b in F₄() ) } ,F₁())