Bac Science 2020 (Probleme)

Program robot;
Uses Wincrt;
Var
  nl,nc,l,c: Integer;
    ch:string;

Function verif (ch:String): Boolean;
Var
  i: Integer;
  test: Boolean;
Begin
  i := 0;
  Repeat
    i := i+1;
    test := ch[i] In ['H','B','D','G'];
  Until (i=Length(ch)) Or (test=False);
  verif := test;
End;

Procedure saisie (Var nl,nc,l,c:Integer;Var ch:String);
Var
  i,j: Integer;
Begin
  Repeat
    Write ('Saisir NL et NC: ');
    Readln (nl);
    Readln (nc);
  Until (nl In [1..100]) And (nc In [1..100]);
  Repeat
    Write ('Saisir la position de départ: ');
    Readln (l);
    Readln (c);
  Until (1<l) And (l<nl) And (1<c) And (c<nc);
  Repeat
    Write ('Saisir le parcours du robot: ');
    Readln (ch);
  Until verif (ch);
End;

Procedure traitement (ch:String;nl,nc,l,c:Integer);
Var
i:integer;
Begin
  i := 0;
  Repeat
    i := i+1;
        case ch[i] Of
            'H':l:=l-1;
            'B':l:=l+1;
            'G':c:=c-1;
            'D':c:=c+1;
        end;
        if (l>nl) or (l<0) or (c<0) or (c>nc) Then
            writeln ('Attention cas de dépassement causé par le pas N°',i);
  Until (i=Length(ch)) or ((l>nl) or (l<0) or (c<0) or (c>nc));
    if (i=Length(ch)) Then
        writeln ('Je suis à la position (',l,',',c,')');
End;
Begin
    saisie (nl,nc,l,c,ch);
    traitement  (ch,nl,nc,l,c);
End.