let Y be non empty set ; :: thesis: for G being Subset of (PARTITIONS Y)
for A, B, C, D, E, F, J being a_partition of Y st G = {A,B,C,D,E,F,J} & A <> B & A <> C & A <> D & A <> E & A <> F & A <> J & B <> C & B <> D & B <> E & B <> F & B <> J & C <> D & C <> E & C <> F & C <> J & D <> E & D <> F & D <> J & E <> F & E <> J & F <> J holds
CompF (B,G) = ((((A '/\' C) '/\' D) '/\' E) '/\' F) '/\' J
let G be Subset of (PARTITIONS Y); :: thesis: for A, B, C, D, E, F, J being a_partition of Y st G = {A,B,C,D,E,F,J} & A <> B & A <> C & A <> D & A <> E & A <> F & A <> J & B <> C & B <> D & B <> E & B <> F & B <> J & C <> D & C <> E & C <> F & C <> J & D <> E & D <> F & D <> J & E <> F & E <> J & F <> J holds
CompF (B,G) = ((((A '/\' C) '/\' D) '/\' E) '/\' F) '/\' J
let A, B, C, D, E, F, J be a_partition of Y; :: thesis: ( G = {A,B,C,D,E,F,J} & A <> B & A <> C & A <> D & A <> E & A <> F & A <> J & B <> C & B <> D & B <> E & B <> F & B <> J & C <> D & C <> E & C <> F & C <> J & D <> E & D <> F & D <> J & E <> F & E <> J & F <> J implies CompF (B,G) = ((((A '/\' C) '/\' D) '/\' E) '/\' F) '/\' J )
{A,B,C,D,E,F,J} = {A,B} \/ {C,D,E,F,J} by ENUMSET1:17
.= {B,A,C,D,E,F,J} by ENUMSET1:17 ;
hence ( G = {A,B,C,D,E,F,J} & A <> B & A <> C & A <> D & A <> E & A <> F & A <> J & B <> C & B <> D & B <> E & B <> F & B <> J & C <> D & C <> E & C <> F & C <> J & D <> E & D <> F & D <> J & E <> F & E <> J & F <> J implies CompF (B,G) = ((((A '/\' C) '/\' D) '/\' E) '/\' F) '/\' J ) by Th42; :: thesis: verum