Hi guys, first post, sorry if it's in the wrong place. Frequent visitor, you seem to help pretty comprehensively. I'm using mathematica to calculate a bell inequality, with a general noisy quantum state. However, when I evaluate it, I get a sequence with an a in the result.. which isn't a declared variable. I'm not really sure what it means, and given the generality of 'a', googling it is pretty much impossible. The question I'm asking is, what on earth is this 'a'? If it was 'i', I'd know how to start looking for a solution, but this is just strange. I should be getting a value of 3.414 or so (maximum violation for a quantum state) Here's an example of what I'm getting Code (Text): Evaluate[B1,q=1] Sequence[2.28222 + 0.0266136 a, 1] 2. Relevant equations Here's the equations I'm using, if they're at all relevant. Code (Text): x = ArcTan[q] A = (Cos[x/2]^2)/2 B = (Sin[x/2]^2)/2 ab00 = A (2 - q) ab01 = B (2 - q) c = (Cos[x/2] + Sin[x/2])/4 d = (Cos[x/2] - Sin[x/2])/4 B1 = ab00 + ab00 + 2 c (q) + 2 q (A) + 2 a (B) + 2 q (d) 3. The attempt at a solution No attempted solution, just too confused!