let Y be non empty set ; for a being Function of Y,BOOLEAN
for G being Subset of (PARTITIONS Y)
for A, B being a_partition of Y holds All ((All (('not' a),A,G)),B,G) '<' Ex (('not' (All (a,B,G))),A,G)
let a be Function of Y,BOOLEAN; for G being Subset of (PARTITIONS Y)
for A, B being a_partition of Y holds All ((All (('not' a),A,G)),B,G) '<' Ex (('not' (All (a,B,G))),A,G)
let G be Subset of (PARTITIONS Y); for A, B being a_partition of Y holds All ((All (('not' a),A,G)),B,G) '<' Ex (('not' (All (a,B,G))),A,G)
let A, B be a_partition of Y; All ((All (('not' a),A,G)),B,G) '<' Ex (('not' (All (a,B,G))),A,G)
( 'not' (Ex ((Ex (a,A,G)),B,G)) = All (('not' (Ex (a,A,G))),B,G) & All (('not' (Ex (a,A,G))),B,G) = All ((All (('not' a),A,G)),B,G) )
by BVFUNC_2:19;
hence
All ((All (('not' a),A,G)),B,G) '<' Ex (('not' (All (a,B,G))),A,G)
by Th40; verum