p9104.pl0

《PL/0的编译器》：PL/0语言是Pascal语言的一个子集

PROGRAM MAIN;
CONST A=10;
VAR B,C;
PROCEDURE P;
VAR D;
 PROCEDURE Q;
 CONST E=5; VAR F;
  PROCEDURE R;
  VAR G;
  BEGIN G:=A+E; F:=G;
    WRITE(G)
  END;
 BEGIN CALL R; WRITE(F);
   F:=A+E*F; WRITE(F,D)
 END;
BEGIN D:=A+B; WRITE(D); CALL Q END;
PROCEDURE S;
BEGIN CALL P; B:=-10; WRITE(B) END;
BEGIN
  B:=8;
  READ(C);
  WHILE C>0 DO
    BEGIN
      WRITE(B); CALL S;
      B:=B+C; WRITE(B);
      READ(C)
    END;
  CALL P
END.