It is a beginner question but I did not find a good explanation so I am asking here. Hope that I received the help from the community.
Today I run a joint null test individually like that
test (tau0=0) (tau1=0) (tau2=0)
And the result is
( 1) tau0 = 0 ( 2) tau1 = 0 ( 3) tau2 = 0 chi2( 3) = 1.12 Prob > chi2 = 0.7717
I am wondering what does the numbers 2 and 3 in chi2(3) mean. I did a search from Wikipedia but I did not fully get it.