let p be Element of REAL 3; p = |[(p . 1),(p . 2),(p . 3)]|
consider x, y, z being Element of REAL such that
A1:
p = <*x,y,z*>
by FINSEQ_2:103;
A2:
p . 1 = x
by A1, FINSEQ_1:45;
p . 2 = y
by A1, FINSEQ_1:45;
hence
p = |[(p . 1),(p . 2),(p . 3)]|
by A1, A2, FINSEQ_1:45; verum