let D be non empty set ; for z being Tuple of 5,D ex d1, d2, d3, d4, d5 being Element of D st z = <*d1,d2,d3,d4,d5*>
let z be Tuple of 5,D; ex d1, d2, d3, d4, d5 being Element of D st z = <*d1,d2,d3,d4,d5*>
A1:
z is Element of D *
by FINSEQ_1:def 11;
len z = 5
by CARD_1:def 7;
then
z in 5 -tuples_on D
by A1;
then
z in { <*d1,d2,d3,d4,d5*> where d1, d2, d3, d4, d5 is Element of D : verum }
by Th5;
hence
ex d1, d2, d3, d4, d5 being Element of D st z = <*d1,d2,d3,d4,d5*>
; verum