Procedure Dobnach(var L: TList; E:TElem); {Добавление элемента в начало списка}
var
 N: TList;
Begin
 new(N);
 writeln('vvedite element');
 readln(data);
 if data='t' then E:=true;
 if data='f' then E:=false;
 N^.Info:=E;
 N^.Next:=L;
 L:=N
end;
procedure Dobend(L: TList; E: TElem);{Добавление элемента в конец списка}
begin
 while L^.Next<>nil do L := L^.Next;
 new(L^.Next );
 L:=L^.Next;
 writeln('vvedite element');
 readln(data);
 if data='t' then E:=true;
 if data='f' then E:=false;
 L^.Info:=E;
 L^.Next:=nil
end;

procedure insert_before(p: plist; x: telem);
var T: plist;
begin
  new(T);
  T^.info := p^.info; T^.next := p^.next;
  p^.next := T;
  p^.info := x
end;
procedure tlist.insert_after(p: plist; x: telem);
var T: plist;
begin
  new(T);
  T^.info := x; T^.next := p^.next;
  p^.next := T
end;

program kurs83(input,output);

Type
  TElem = boolean;
  TList = ^TNode;
  TNode = record
    Info: TElem;
    Next: TList
  end;

var
  X: integer;
  z:integer;
  L:TList;
  E:TElem;

function get_boolean: boolean;
var ch: char;
begin
  write('enter [f, t]: '); readln(ch);
  get_boolean := upcase(ch) = 'T';
end;

Procedure Insert(var L: TList; E: TElem);
var N: TList;
Begin
  new(N);
  N^.Info := E;
  N^.Next:=L;
  L:=N
End;

procedure Append(L: TList; E: TElem);
begin
  while L^.Next <> nil do L := L^.Next;
  new(L^.Next);
  L:=L^.Next;
  L^.Info := E;
  L^.Next := nil
end;

procedure InsertAfter(L: TList; X: Integer; E: TElem);
Var N: TList;
begin
  while (L^.next <> nil) and (X > 1) do begin
    L := L^.next; Dec(X)
  end;

  if X = 1 then begin
    New(N);
    N^.info := E;
    N^.next := L^.next;
    L^.next := N;
  end;

end;

Procedure Del (Var L: Tlist);
Var r: Tlist;
Begin
  writeln('kakoy element udalit?');
  r:=L^.Next;
  L^.Next:=L^.Next^.next;
  r^.Next:=nil
End;

procedure Active(var L: TList);
var
  H: TList;
  P: TList;
begin
  P := nil;
  while L<>nil do begin
    H := L^.Next;
    L^.Next := P;
    P := L;
    L:=H
  end;
  L :=P
end;

procedure Print(L: TList );
begin
  write('< ');
  while L <> nil DO begin
    write( L^.Info );
    If L^.Next <> nil then write(',');
    L := L^.Next
  end;
  writeln(' >')
end;


begin
  L := nil;
  repeat
    writeln('1-Noviy spisok');
    writeln('2-Dob elem v konec');
    writeln('3-Dob elem v nachalo');
    writeln('4-Deystvie');
    writeln('5-Print');
    writeln('6-del');
    writeln('7-insert before');
    writeln('8-Vihod');
    writeln('vvedite punkt menu:');
    readln(z);
    case z of
      1, 3: Insert(L, get_boolean);
      2   : Append(L, get_boolean);
      4   : Active(L);
      5   : Print(L);
      6   : del(L);
      7   :
        begin
          write('insert before element #'); readln(X);
          if x = 1 then Insert(L, get_boolean)
          else InsertAfter(L, X - 1, get_boolean);
        end;
    end;
  until z = 8;
end.

Procedure DelAfter(Var L: Tlist; X: integer);
Var
  T, r: Tlist;
Begin

  if X = 0 then begin
    T := L;
    L := L^.next;
    dispose(T);
  end
  else begin

    r := L;
    while (r^.next <> nil) and (X > 1) do begin
      r := r^.next; Dec(X)
    end;
    if X = 1 then begin

      T := r^.next;
      if T <> nil then r^.next := T^.next
      else r^.next := T

    end;

  end;

End;

...
{ Вызов: }
    case z of
      ...
      6   :
        begin
          write('delete element #'); readln(X);
          DelAfter(L, X - 1);
        end;
      ...
    end;