Description does not specify that the shortest route must be taken.

Ruby transaltion Kumited, please review and approve!

I'm really confused on one of the test cases. (I don't think this is a spoiler because it's just about the test case.) The test case is: (aOR!b)AND(cOR!d)AND(!cOR!dOR!eOR!f)AND(eOR!g)AND(!fORg)AND(bOR!c)AND(cORdOReORf)AND(!aORf)AND(dOR!e)AND(aORbORg)
I think the feedback says that this test case is supposed to be True/valid (because my program gives the answer False), but I don't understand why.

As far as I can tell, if a is True, !aORf means f must be True (because !a is False), !fORg means g must be True, eOR!g means e must be True, dOR!e means d must be True, cOR!d means c must be True, and then !cOR!dOR!eOR!f is False because f, e, d, and c are True. So the solution a = True doesn't work.

If a is False, aOR!b means b must be False (because a is False in aOR!b, so !b must be True and b must be False), and then bOR!c means c must be False, cOR!d means d must be false, dOR!e means e must be False, and eOR!g means g must be False, making aORbORg False.

Since a cannot be True or False with all the statements evaluating to True, why is this statement valid? I'm clearly missing something here, maybe not even understanding the Kata as a whole, but since I can't even understand the test case, it's really hard to get my program to understand it. Can anyone help me out here?

Needs random tests.

In the test cases and sample tests for Python, the parameters to assert_equals are being given in the wrong order. It should be test.assert_equals(is_possible(expr),expected_value). As it is, if the user's solution returns True when False is expected, it will say False should equal True, when it should say True should equal False.