let Y be non empty set ; for a being Element of Funcs Y,BOOLEAN
for G being Subset of (PARTITIONS Y)
for A, B being a_partition of Y holds All ('not' (Ex a,A,G)),B,G '<' Ex ('not' (All a,B,G)),A,G
let a be Element of Funcs Y,BOOLEAN ; for G being Subset of (PARTITIONS Y)
for A, B being a_partition of Y holds All ('not' (Ex 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 ('not' (Ex a,A,G)),B,G '<' Ex ('not' (All a,B,G)),A,G
let A, B be a_partition of Y; All ('not' (Ex 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
by BVFUNC_2:21;
hence
All ('not' (Ex a,A,G)),B,G '<' Ex ('not' (All a,B,G)),A,G
by Th19; verum