Здравствуйте, kondrat322!

Смотрите код:
[code lang=pascal]const
n=10;
type
tMas=array[1..n,1..n]of integer;
procedure InputArray(var a:tMas);
var
b,c:integer;
begin
for b:=1 to n do
for c:=1 to n do
begin
write('enter A[',b:2,',',c:2,']:=');
readln(a[b,c]);
end;
end;
procedure ShowArray(a:tMas);
var
b,c:integer;
begin
for b:=1 to n do
begin
for c:=1 to n do
write(a[b,c]:3);
writeln;
end;
end;
procedure SummaSpecial(a:tMas;b,c:integer;var d:integer);
var
e,f:integer;
begin
d:=0;
for e:=1 to n do
for f:=e to n do
if a[e,f]in [b..c]then d:=d+a[e,f];
end;
var
a:tMas;
k,l,s:integer;
begin
InputArray(a);
ShowArray(a);
write('enter k:=');readln(k);
repeat
write('enter l(>',k,'):=');
readln(l);
until l>k;
SummaSpecial(a,k,l,s);
writeln('result:=',s);
end.[/code]
Удачи!