Hi,
I'm not an experinced user and I've spent already several ours trying to identify the problem. Randomly it happens that some variables are not recognized. See the print screen. I'm suspecting 1) settings/preferences are not correct or 2) mathcad 15 has a bug. I reinstalled it, cleaned the registries. Not a solution. I attached the file also. I would apreciate your help.
Best regards,
GS
