PROGRAM demonstrate_conditional_branching;

VAR one,two,three  : INTEGER;

BEGIN  (* main program *)
  one := 1;           (* these are to have some numbers *)
  two := 2;           (* to use for illustrations *)
  three := 3;

  IF three = (one + two) THEN        (* Example 1 *)
    WRITELN('three is equal to one plus two');

  IF three = 3 THEN                  (* Example 2 *)
  BEGIN
    WRITE('three is ');
    WRITE('equal to ');
    WRITE('one plus two');
    WRITELN;
  END;

  IF two = 2 THEN                    (* Example 3 *)
    WRITELN('two is equal to 2 as expected')
  ELSE
    WRITELN('two is not equal to 2... rather strange');

  IF two = 2 THEN                    (* Example 4 *)
    IF one = 1 THEN
      WRITELN('one is equal to one')
    ELSE
      WRITELN('one is not equal to one')
  ELSE
    IF three = 3 THEN
      WRITELN('three is equal to three')
    ELSE
      WRITELN('three is not equal to three');

END.  (* main program *)