Делаю курсовую.программа для решения дифференциальных уравнений произвольного порядка

program kurs;
const jm = 2;
type mas = array[1..jm] of real;
var
y0,y, f: mas;
t0, t, h, tk: real;
j: 1..jm;
i, l: integer;
 
procedure RP(var t0: real; var y, f: mas);
begin
f[1] := y[2];
f[2]:=(y0[2]*y0[2])/y0[1]-y0[1]*y0[2]*ln(y0[1]);
end;
 
procedure EU(var t0, h, t: real; var y0, y, f: mas);
var
j: 1..jm;
begin
RP(t0, y0, f);
for j := 1 to jm do
y[j] := y0[j] + h * f[j];
t := t0 + h;
end;
 
begin
t0 := 0.5; tk := 1.0;
y[2] := 1.0;
h := 0.001; l := 0;
i := 100;
while t <= tk do
begin
EU(t0, h, t,y0, y, f);
if (l mod i) = 0 then writeln('t =', t0, ' ', 'y1 =', y[1]:5:5, ' ', 'y2= ', y[2]:5:5);
l := l + 1;
for j := 1 to jm do
y0[j] := y[j];
t0 := t;
end;
end.