Coef    S.E.   Wald Z Pr(>|Z|)
     Intercept -1.5790 0.1452 -10.87 <0.0001
     A1=1       0.7439 0.4004   1.86 0.0632
     A2         0.2525 0.1364   1.85 0.0641

NE1= Y~A1 #BINARY
 NE2= Y~A2 #CONTINUOUS
 system=list(NCAT=NE1, NDIM=NE2)
 fitsur=systemfit(system, method="SUR",data=MMM)
 restrict1="NE1_A1 - NE2_A2"
 linearHypothesis(fitsur,restrict1,test="Chisq")