{TURUN -- A sample program written in Tiny Pascal }
  var I, J, K, PROBLEM;
  
  {*********************}
  function ISLESS(N1, N2);
  begin  {returns 1 if n1<n2, 0 otherwise}
    if n2-n1 then isless:=1   {truth value test is >0}
    else isless:=0;
    end;
    
  function ADDEMUP(LOWER, UPPER, SUM);
  begin end;    {makes it a forward declaration}
  
  {*********************}
  function ISEQUAL(N1, N2);
  begin
    if n2-n1 then isequal:=0   {false}
    else
    if n1-n2 then isequal:=0
    else isequal:=1;
    end;
    
  {***********************}
  function ADDEMUP(LOWER, UPPER, SUM);
        {SUM is a local}
  begin
    sum:=0;
    while isless(lower, upper) do begin
      sum:=sum+lower;
      lower:=lower+1;
      end;
    addemup:=sum+lower;  { the last one was left out }
    end;

  {*********************}
  function MAIN(SUM, UPPER);
  begin
    i:=1;
    j:=i+5;
    k:=j-16;
    problem:=i+(j*k);
    writeln('I: ', i, ' J: ', j, ' K: ', k, ' Problem: ', problem);
    write('Enter upper ');
    upper:=read;
    sum:=addemup(1, upper);  {sum of integers 1..upper}
    if isequal(sum, (upper*(upper+1))/2) then
      writeln('Sum = ', sum)
    else begin
      writeln('BUG: Sum = ', sum, '; should be ',
                 (upper*(upper+1))/2);
      end;
    end;