let X1, X2, X3, X4, X5, X6, X7, X8 be set ; :: thesis: ( X1 <> {} & X2 <> {} & X3 <> {} & X4 <> {} & X5 <> {} & X6 <> {} & X7 <> {} & X8 <> {} implies for x being Element of [:X1,X2,X3,X4,X5,X6,X7,X8:] holds
( x `1 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `1 & x `2 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `3 = (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 ) )
assume A1: ( X1 <> {} & X2 <> {} & X3 <> {} & X4 <> {} & X5 <> {} & X6 <> {} & X7 <> {} & X8 <> {} ) ; :: thesis: for x being Element of [:X1,X2,X3,X4,X5,X6,X7,X8:] holds
( x `1 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `1 & x `2 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `3 = (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
let x be Element of [:X1,X2,X3,X4,X5,X6,X7,X8:]; :: thesis: ( x `1 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `1 & x `2 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `3 = (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `1 = [(x `1 ),(x `2 )] `1 by MCART_1:7
.= ([[(x `1 ),(x `2 )],(x `3 )] `1 ) `1 by MCART_1:7
.= ([(x `1 ),(x `2 ),(x `3 )] `1 ) `1 by MCART_1:def 3
.= (([[(x `1 ),(x `2 ),(x `3 )],(x `4 )] `1 ) `1 ) `1 by MCART_1:7
.= (([(x `1 ),(x `2 ),(x `3 ),(x `4 )] `1 ) `1 ) `1 by MCART_1:def 4
.= ((([[(x `1 ),(x `2 ),(x `3 ),(x `4 )],(x `5 )] `1 ) `1 ) `1 ) `1 by MCART_1:7
.= (((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `1 ) `1 ) `1 ) `1 ) `1 by MCART_1:7
.= ((((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `1 ) `1 ) `1 ) `1 ) `1 by MCART_1:7
.= (((((([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `1 by MCART_1:7
.= ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `1 by A1, Th23 ; :: thesis: ( x `2 = ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `3 = (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `2 = [(x `1 ),(x `2 )] `2 by MCART_1:7
.= ([[(x `1 ),(x `2 )],(x `3 )] `1 ) `2 by MCART_1:7
.= ([(x `1 ),(x `2 ),(x `3 )] `1 ) `2 by MCART_1:def 3
.= (([[(x `1 ),(x `2 ),(x `3 )],(x `4 )] `1 ) `1 ) `2 by MCART_1:7
.= (([(x `1 ),(x `2 ),(x `3 ),(x `4 )] `1 ) `1 ) `2 by MCART_1:def 4
.= ((([[(x `1 ),(x `2 ),(x `3 ),(x `4 )],(x `5 )] `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= ((((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((((([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= ((((((x `1 ) `1 ) `1 ) `1 ) `1 ) `1 ) `2 by A1, Th23 ; :: thesis: ( x `3 = (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 & x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `3 = [[(x `1 ),(x `2 )],(x `3 )] `2 by MCART_1:7
.= [(x `1 ),(x `2 ),(x `3 )] `2 by MCART_1:def 3
.= ([[(x `1 ),(x `2 ),(x `3 )],(x `4 )] `1 ) `2 by MCART_1:7
.= ([(x `1 ),(x `2 ),(x `3 ),(x `4 )] `1 ) `2 by MCART_1:def 4
.= (([[(x `1 ),(x `2 ),(x `3 ),(x `4 )],(x `5 )] `1 ) `1 ) `2 by MCART_1:7
.= ((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= ((((([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((((x `1 ) `1 ) `1 ) `1 ) `1 ) `2 by A1, Th23 ; :: thesis: ( x `4 = ((((x `1 ) `1 ) `1 ) `1 ) `2 & x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `4 = [[(x `1 ),(x `2 ),(x `3 )],(x `4 )] `2 by MCART_1:7
.= [(x `1 ),(x `2 ),(x `3 ),(x `4 )] `2 by MCART_1:def 4
.= ([[(x `1 ),(x `2 ),(x `3 ),(x `4 )],(x `5 )] `1 ) `2 by MCART_1:7
.= (([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `1 ) `1 ) `2 by MCART_1:7
.= ((([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `1 ) `1 ) `2 by MCART_1:7
.= ((((x `1 ) `1 ) `1 ) `1 ) `2 by A1, Th23 ; :: thesis: ( x `5 = (((x `1 ) `1 ) `1 ) `2 & x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `5 = [[(x `1 ),(x `2 ),(x `3 ),(x `4 )],(x `5 )] `2 by MCART_1:7
.= ([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `1 ) `2 by MCART_1:7
.= (([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `1 ) `2 by MCART_1:7
.= ((([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `1 ) `2 by MCART_1:7
.= (((x `1 ) `1 ) `1 ) `2 by A1, Th23 ; :: thesis: ( x `6 = ((x `1 ) `1 ) `2 & x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `6 = [[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 )],(x `6 )] `2 by MCART_1:7
.= ([[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `1 ) `2 by MCART_1:7
.= (([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `1 ) `2 by MCART_1:7
.= ((x `1 ) `1 ) `2 by A1, Th23 ; :: thesis: ( x `7 = (x `1 ) `2 & x `8 = x `2 )
thus x `7 = [[(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 )],(x `7 )] `2 by MCART_1:7
.= ([(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `1 ) `2 by MCART_1:7
.= (x `1 ) `2 by A1, Th23 ; :: thesis: x `8 = x `2
thus x `8 = [(x `1 ),(x `2 ),(x `3 ),(x `4 ),(x `5 ),(x `6 ),(x `7 ),(x `8 )] `2 by MCART_1:7
.= x `2 by A1, Th23 ; :: thesis: verum