var
a:array[1..20,1..20] of integer;
n,i,k,l,x:integer;
...............................................
for i:=1 to n do
begin
x:=a[i,k];
a[i,k]:=a[i,l];
a[i,l]:=x;
end;
var
a:array[1..20,1..20] of integer;
n,i,k,l,x:integer;
...............................................
for i:=1 to n do
begin
x:=a[i,k];
a[i,k]:=a[i,l];
a[i,l]:=x;
end;