Using this code,you can see,same input, but the output are different. So weird!

If I copy this code here, it outputs normally. So what's the problem?

Ps:I use "10.4.0 for Microsoft Windows (64-bit) (February 26, 2016)".

I want to show how to reproduce this phenomenon. enter image description here

  • $\begingroup$ Reproduced in v9.0.1 and v8.0.4… how did you create these? $\endgroup$ – xzczd May 9 '16 at 12:12
  • $\begingroup$ @xzczd When I read the http://www.mathprogramming-intro.org/download/MathProgrammingIntro.pdf,it is the first code in the section $\endgroup$ – partida May 9 '16 at 12:16
  • $\begingroup$ If you look at the box expressions of the two lines, they are different. This is perhaps caused by pasting code from that pdf file $\endgroup$ – vapor May 9 '16 at 13:58
  • $\begingroup$ @happyfish I didn't copy it from pdf file.I type it letter by letter. $\endgroup$ – partida May 9 '16 at 14:01
  • 1
    $\begingroup$ @partida Whether it is a bug depends on how you created it. If all these can be done by typing and you can tell a reproducible procedure, it is likely to be a bug. $\endgroup$ – vapor May 9 '16 at 14:25