Is there some import I need to do for defining variables?

edit

I have been running Sage 6.6 through VirtualBox and whenever I define a variable I get an error, like for example (for a,b,c = var('a,b,c')):

File "<stdin>", line 1, in <module>
  File "_sage_input_25.py", line 10, in <module>
    exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("YSxiLGMgPSB2YXIo4oCZYSxiLGPigJkpCnFlID0gKGEqeF4yICsgYip4ICsgYyA9PSAwKQpwcmludCBzb2x2ZShxZSwgeCk="),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))
  File "", line 1, in <module>

  File "/tmp/tmpAUEAbf/___code___.py", line 3
    a,b,c = var(’a,b,c’)
                ^
SyntaxError: invalid syntax