I have observed that in Mathematica 10.0 sometimes the variables are unexpectedly cleared when they are used. This did not happen in previous versions of Mathematica. I enclose an example of .nb file where this happens. (The last two input lines are not properly executed).
I have observed that this does not happen when the Clear command of the variables in question are not put in the same cell as that of the definition of the variables.
But I have the habit of clearing (before) the variables at the same cell where they are defined; as mentioned in previous versions it worked OK.
Could anybody check that the error is reproduced in his/her Mathematica 10.0? Thanks in advance.
With the new version 10.0.2 of Mathematica this issue seems to have been solved.
Thanks to the people of Wolfram Research!
I have checked now that the behavior of the "bug" depends on the machine the previous .nb is run on.
-On my home machine/license (10.0.1 in Win 8.1, 64 bits) the "bug" does appear as in the notebook provided:
the last outputs are then
-On my office machine/license (10.0.1 in Win 7, 32 bits) the "bug" does not appear, the last outputs are correctly
I really do not understand why the same program behaves differently on different machines.
Perhaps it is a function of the number of bits of the operating system, but Tim reports that his
Win 7 OS has 64 bits as well...
Or perhaps the difference is on Win 7 / Win 8.1...
What a mystery...
I'm not sure that I understand your "bug", but the last two lines do execute on my machine (10.0.1 in Windows 7 64 bit).
The curious thing is that not all variables are cleared when that happens; so it is not a kernel crash.
I use 10.0.1 on Windows, 64 bits. Maybe it is a problem of the Windows versión.
I am not seeing this behavior (in 10.0.1, on Linux). I can say that, generally speaking, when all definitions have been cleared it is an indication that the kernel has crashed.