let X1, X2, X3, X4, X5 be set ; for A1 being Subset of
for A2 being Subset of
for A3 being Subset of
for A4 being Subset of
for A5 being Subset of
for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let A1 be Subset of ; for A2 being Subset of
for A3 being Subset of
for A4 being Subset of
for A5 being Subset of
for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let A2 be Subset of ; for A3 being Subset of
for A4 being Subset of
for A5 being Subset of
for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let A3 be Subset of ; for A4 being Subset of
for A5 being Subset of
for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let A4 be Subset of ; for A5 being Subset of
for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let A5 be Subset of ; for x being Element of [:X1,X2,X3,X4,X5:] st x in [:A1,A2,A3,A4,A5:] holds
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
let x be Element of [:X1,X2,X3,X4,X5:]; ( x in [:A1,A2,A3,A4,A5:] implies ( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 ) )
assume A1:
x in [:A1,A2,A3,A4,A5:]
; ( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
then reconsider y = x as Element of [:A1,A2,A3,A4,A5:] ;
A2 <> {}
by A1, Th13;
then A2:
y `2 in A2
;
A4 <> {}
by A1, Th13;
then A3:
y `4 in A4
;
A3 <> {}
by A1, Th13;
then A4:
y `3 in A3
;
A5 <> {}
by A1, Th13;
then A5:
y `5 in A5
;
A1 <> {}
by A1, Th13;
then
y `1 in A1
;
hence
( x `1 in A1 & x `2 in A2 & x `3 in A3 & x `4 in A4 & x `5 in A5 )
by A2, A4, A3, A5, Th33; verum