In their article, The Early Deveopment of Programming Languages, Donald E. Knuth and Luis Trabb conclude their article with computer code:

The TPK alogrithm in the international algebraic language, also known as ALGOL. TPK here stands for Trabb-Pardo Knuth. This was a kind of Hello, World program (according to the Wik), although it seems more a kin to the WRT idea of benchmarking, not so much can you do this initial act, as how does this programming language express this set of processes?

Heres the code:

procedure TPK(a[] =: b[]);
array (a[0:10], b[0:21]);
comment Given 11 input values a[0],,a[10], this procedure produces 22 output values b[0],,b[21], according to the classical TPK algorithm:
begin for i = 10(-1)0;
begin y:= f(a[i]);
f(t) := sqrt(abs(t))+5 x t ^ 3 v ;
if (y > 400); y := 999;
b[20-2 x i] := i;
b[21-2 x i] := y;
end;
return;
integer (i)
end TPK.

What does it mean to end your essay in code, to let the code speak for itself?