let Y be non empty set ; :: thesis: for G being Subset of (PARTITIONS Y)
for A, B, C, D, E, F being a_partition of Y st G is independent & G = {A,B,C,D,E,F} & A <> B & A <> C & A <> D & A <> E & A <> F & B <> C & B <> D & B <> E & B <> F & C <> D & C <> E & C <> F & D <> E & D <> F & E <> F holds
CompF D,G = (((A '/\' B) '/\' C) '/\' E) '/\' F
let G be Subset of (PARTITIONS Y); :: thesis: for A, B, C, D, E, F being a_partition of Y st G is independent & G = {A,B,C,D,E,F} & A <> B & A <> C & A <> D & A <> E & A <> F & B <> C & B <> D & B <> E & B <> F & C <> D & C <> E & C <> F & D <> E & D <> F & E <> F holds
CompF D,G = (((A '/\' B) '/\' C) '/\' E) '/\' F
let A, B, C, D, E, F be a_partition of Y; :: thesis: ( G is independent & G = {A,B,C,D,E,F} & A <> B & A <> C & A <> D & A <> E & A <> F & B <> C & B <> D & B <> E & B <> F & C <> D & C <> E & C <> F & D <> E & D <> F & E <> F implies CompF D,G = (((A '/\' B) '/\' C) '/\' E) '/\' F )
assume A1: ( G is independent & G = {A,B,C,D,E,F} & A <> B & A <> C & A <> D & A <> E & A <> F & B <> C & B <> D & B <> E & B <> F & C <> D & C <> E & C <> F & D <> E & D <> F & E <> F ) ; :: thesis: CompF D,G = (((A '/\' B) '/\' C) '/\' E) '/\' F
{A,B,C,D,E,F} = {A,B} \/ {C,D,E,F} by ENUMSET1:52
.= {A,B} \/ ({C,D} \/ {E,F}) by ENUMSET1:45
.= {A,B} \/ {D,C,E,F} by ENUMSET1:45
.= {A,B,D,C,E,F} by ENUMSET1:52 ;
hence CompF D,G = (((A '/\' B) '/\' C) '/\' E) '/\' F by A1, Th36; :: thesis: verum