# Problem with Probability and MultivariateHypergeometricDistribution (bug?)

Using the input

Probability[z[1] >= 1 && z[2] >= 1 && z[5] >= 1,
Array[z, 6] \[Distributed] MultivariateHypergeometricDistribution[4, {4, 4, 0, 0, 4, 0}]] // Short


Returned is

1/495 Hold[Function[{Compile$$2072,<<4>>,Compile$$2077},Boole[<<1>>]]][0,<<5>>]+<<14>>

Releasing the hold gives the correct result, but it appears there's an issue when there are zero elements in the count vector.

On 10.3.1 Windows. Works fine in 9.x Windows.

Confirmations?

• Same on Windows 7 Mathematica 10.4.1 and essentially the same on Windows 7 Mathematica 11.0.1. (By "essentially" I mean the Function[{Compile... doesn't show but the Hold's show.)
– JimB
Commented Feb 21, 2017 at 5:20
• Happens on 11.0 on Manjaro 16.10.3 too. Using ReleaseHold I get 32/55 Commented Feb 21, 2017 at 7:33
• Same behaviour Windows 10 Mathematica version 11 Commented Feb 22, 2017 at 3:52
• ReleaseHold@ Probability[z[1] >= 1 && z[2] >= 1 && z[5] >= 1, Array[z, 6] \[Distributed] MultivariateHypergeometricDistribution[4, {4, 4, 0, 0, 4, 0}]] evaluates to 32/55 Commented Feb 22, 2017 at 4:12
• NProbability does give the correct result at least. (These things are probably "features", e.g. they check that user do not fall asleep solving problems in Mathematica...)
– gwr
Commented Feb 22, 2017 at 9:57