２元
－－－－－
k:=0:
j:=0;
input f$,g$;
input h,e;
input n;
input l;
dim x(n+1),y(n+1),z(n+1),u(l+1),v(l+1),s(l+1),t(l+1);
input x(1),y(1),z(1);
for i:=1 to n;
x:=x(i);
y:=y(i);
z:=z(i);
t(1):=y+h*val(f$);
v(1):=z+h*val(g$);
a:=2;
for j:=1 to l;
a1:=a;
x:=x(i);
y:=y(i);
z:=z(i);
for k:=1 to a;
f:=val(f$);
g:=val(g$);
x:=x+h/a1;
y:=y+h/a1*f;
z:=z+h/a1*g;
next k;
s(1):=y;
u(1):=z;
f1:=1;
for k:=1 to j;
f1:=f1*2;
s(k+1):=s(k)+(s(k)-t(k))/(f1-1);
u(k+1):=u(k)+(u(k)-v(k))/(f1-1);
if abs(s(k+1)-s(k)<=s(k)*e and abs(u(k+1)-u(k)<=u(k)*e then l1;
next k;
j1:=j+1;
for k:=1 to j1;
t(k):=s(k);
v(k):=u(k);
next k;
a:=a*2;
next j;
go l2;
label l1;
x(i+1):=x(i)+h;
y(i+1):=s(k+1);
z(i+1):=u(k+1);
next i;
label l2;
input h1,h2;
if h2=0 then l3;
for i:=1 to n step h1/h;
print x(i),y(i);
next i;
end;
label l3;
for i:=1 to n step h1/h;
print x(i_),tab(3),y(i),z(i);
next i;
end;