let Y be non empty set ; :: thesis: for G being Subset of (PARTITIONS Y)
for u, a being Element of Funcs Y,BOOLEAN
for PA being a_partition of Y st u is_independent_of PA,G holds
All (u 'eqv' a),PA,G '<' u 'eqv' (All a,PA,G)

let G be Subset of (PARTITIONS Y); :: thesis: for u, a being Element of Funcs Y,BOOLEAN
for PA being a_partition of Y st u is_independent_of PA,G holds
All (u 'eqv' a),PA,G '<' u 'eqv' (All a,PA,G)

let u, a be Element of Funcs Y,BOOLEAN ; :: thesis: for PA being a_partition of Y st u is_independent_of PA,G holds
All (u 'eqv' a),PA,G '<' u 'eqv' (All a,PA,G)

let PA be a_partition of Y; :: thesis: ( u is_independent_of PA,G implies All (u 'eqv' a),PA,G '<' u 'eqv' (All a,PA,G) )
assume u is_independent_of PA,G ; :: thesis: All (u 'eqv' a),PA,G '<' u 'eqv' (All a,PA,G)
then A1: u is_dependent_of CompF PA,G by Def8;
A2: ( 'not' FALSE = TRUE & 'not' TRUE = FALSE ) by MARGREL1:41;
let z be Element of Y; :: according to BVFUNC_1:def 15 :: thesis: ( not (All (u 'eqv' a),PA,G) . z = TRUE or (u 'eqv' (All a,PA,G)) . z = TRUE )
assume A3: (All (u 'eqv' a),PA,G) . z = TRUE ; :: thesis: (u 'eqv' (All a,PA,G)) . z = TRUE
A4: ( z in EqClass z,(CompF PA,G) & EqClass z,(CompF PA,G) in CompF PA,G ) by EQREL_1:def 8;
per cases ( ( ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
u . x = TRUE ) & ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
a . x = TRUE ) ) or ( ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
u . x = TRUE ) & ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not a . x = TRUE ) ) or ( ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not u . x = TRUE ) & ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
a . x = TRUE ) ) or ( ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not u . x = TRUE ) & ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not a . x = TRUE ) ) )
;
suppose A5: ( ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
u . x = TRUE ) & ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
a . x = TRUE ) ) ; :: thesis: (u 'eqv' (All a,PA,G)) . z = TRUE
then A6: (All a,PA,G) . z = TRUE by BVFUNC_1:def 19;
A7: u . z = TRUE by A4, A5;
(u 'eqv' (All a,PA,G)) . z = 'not' ((u . z) 'xor' ((All a,PA,G) . z)) by BVFUNC_1:def 12
.= TRUE by A2, A6, A7, MARGREL1:49 ;
hence (u 'eqv' (All a,PA,G)) . z = TRUE ; :: thesis: verum
end;
suppose A8: ( ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
u . x = TRUE ) & ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not a . x = TRUE ) ) ; :: thesis: (u 'eqv' (All a,PA,G)) . z = TRUE
then consider x1 being Element of Y such that
A9: ( x1 in EqClass z,(CompF PA,G) & a . x1 <> TRUE ) ;
A10: u . x1 = TRUE by A8, A9;
A11: a . x1 = FALSE by A9, XBOOLEAN:def 3;
(u 'eqv' a) . x1 = 'not' ((u . x1) 'xor' (a . x1)) by BVFUNC_1:def 12
.= 'not' (FALSE 'or' TRUE ) by A2, A10, A11
.= 'not' TRUE by BINARITH:7
.= FALSE by MARGREL1:41 ;
hence (u 'eqv' (All a,PA,G)) . z = TRUE by A3, A9, BVFUNC_1:def 19; :: thesis: verum
end;
suppose A12: ( ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not u . x = TRUE ) & ( for x being Element of Y st x in EqClass z,(CompF PA,G) holds
a . x = TRUE ) ) ; :: thesis: (u 'eqv' (All a,PA,G)) . z = TRUE
then consider x1 being Element of Y such that
A13: ( x1 in EqClass z,(CompF PA,G) & u . x1 <> TRUE ) ;
A14: u . x1 = FALSE by A13, XBOOLEAN:def 3;
A15: a . x1 = TRUE by A12, A13;
(u 'eqv' a) . x1 = 'not' ((u . x1) 'xor' (a . x1)) by BVFUNC_1:def 12
.= 'not' (TRUE 'or' FALSE ) by A2, A14, A15
.= 'not' TRUE by BINARITH:7
.= FALSE by MARGREL1:41 ;
hence (u 'eqv' (All a,PA,G)) . z = TRUE by A3, A13, BVFUNC_1:def 19; :: thesis: verum
end;
suppose A16: ( ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not u . x = TRUE ) & ex x being Element of Y st
( x in EqClass z,(CompF PA,G) & not a . x = TRUE ) ) ; :: thesis: (u 'eqv' (All a,PA,G)) . z = TRUE
then A17: (All a,PA,G) . z = FALSE by BVFUNC_1:def 19;
consider x1 being Element of Y such that
A18: ( x1 in EqClass z,(CompF PA,G) & u . x1 <> TRUE ) by A16;
u . x1 = u . z by A1, A4, A18, BVFUNC_1:def 18;
then A19: u . z = FALSE by A18, XBOOLEAN:def 3;
(u 'eqv' (All a,PA,G)) . z = 'not' ((u . z) 'xor' ((All a,PA,G) . z)) by BVFUNC_1:def 12
.= TRUE by A2, A17, A19, MARGREL1:49 ;
hence (u 'eqv' (All a,PA,G)) . z = TRUE ; :: thesis: verum
end;
end;