...THEN
XPDF=1.0D0
DO I=1,TOTLOAD
CALL PDF_NORM(X(I),MEAN_X(I),SD_X(I),PDF,INTEST)
XPDF=XPDF*PDF
END DO
ELSE
CALL JOINT_PDF_NORM_NX3(X,IX,MEAN_X,IMEAN_X,SD_X,ISD_X,COV_X,&
&ICOV_X,JCOV_X,INV_COV_X,IINV_COV_X,&
&JINV_COV_X,DET_COV_X,NX,XPDF,INTEST)
END...