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I'm trying to test the following logical statement:

state = {{1,1,1}};
Or[state != 0, state != Null]

but it's returning False rather than True as I expect it to.

I ran the following TrueQ tests, getting the following results:

TrueQ[Or[{{1, 1, 1}} != 0, {{1, 1, 1}} != Null]]
TrueQ[{{1, 1, 1}} !=  0]
TrueQ[{{1, 1, 1}} != Null]

False

False

False

I'm not sure why I'm getting these results: I don't understand why TrueQ is failing to resolve as True in these situations. What can I do to make the logical test give me the results I'm looking for -- namely, when state is either 0 or Null, I get False, and get True otherwise?

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    $\begingroup$ You probably want =!= instead of !=. $\endgroup$
    – AccidentalFourierTransform
    Commented Aug 12, 2019 at 22:21
  • $\begingroup$ @AccidentalFourierTransform Yup, that worked! Thank you! If you add this as the answer I'll accept it. $\endgroup$
    – Natavi
    Commented Aug 12, 2019 at 22:23
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    $\begingroup$ But why use TrueQ at all? {{1, 1, 1}} =!= 0 evaluates to True directly. $\endgroup$
    – march
    Commented Aug 12, 2019 at 22:50
  • $\begingroup$ TrueQ returns True if and only if its argument is identically equal to True. Now {{1, 1, 1}} != Null remains unevaluated and hence is not True, which means TrueQ returns False. $\endgroup$
    – Greg Hurst
    Commented Aug 13, 2019 at 12:43

1 Answer 1

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You probably want =!= instead of !=. See Unequal v UnsameQ for more details.

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