The Concept of Action  37  The sequence of statements between the symbols repeat and until  is executed at least once. After each execution of the sequence of  statements the Boolean expression is evaluated. Repeated execution is  continued until the expression becomes true. Because the expression is  evaluated for every iteration, you should be careful to keep it as simple  as possible.  program RepeatExample(Input,Output)i  { Program 4.4 - Compute the Nth partial sum of the  harmonic series  H(N)  =  1 +  1/2 +  1/3 +  +  l/N  using a  repeat statement for iteration.  var  N:  Integeri  H:  Reali  begin  Read(Input,N)i  Write(Output,N)i  H  :  =  Oi  repeat  H := H +  l/Ni  N.- N - 1  until N  =  Oi  Writeln(Output,H)  end  .  Produces as results:  102.928968E+00  The above program performs correctly for  N  >  o. Consider what  happens if  N  <= o. The while-version of the same program is correct  for all  N, including N  =  o.  Note that it is a sequence of statements that the repeat statement  executes; a bracketing pair begin ... end would be redundant (but not  incorrect) .  The  for statement  indicates that a statement be repeatedly executed  while a progression of values is assigned to the  control variable  of the  for statement. It has the general form:  4.D.3  The for statement 