C FUD=X*(U+D)
C FS=X*2(UBAR+DBAR+SBAR) AND UBAR=DBAR=SBAR
C*******************************************************
+C PH Make sure X1 belongs to [0,1]
+ IF (X1.LT.0.D0) X1=0.D0
+ IF (X1.GT.1.D0) X1=1.D0
FUD1=CNUD*X1**AT1*(1.D0-X1)**AT2*(1.D0+GMUD*X1)
FS1=CAS*X1**AS*(1.D0-X1)**BS*(1.D0+APHS*X1
& +BTAS*X1**2+GMS*X1**3)
F(1,7)=CAG*X1**AG*(1.D0-X1)**BG*(1.D0+APHG*X1
& +BTAG*X1**2+GMG*X1**3)
C
+C PH Make sure X2 belongs to [0,1]
+ IF (X2.LT.0.D0) X2=0.D0
+ IF (X2.GT.1.D0) X2=1.D0
FUD2=CNUD*X2**AT1*(1.D0-X2)**AT2*(1.D0+GMUD*X2)
FS2=CAS*X2**AS*(1.D0-X2)**BS*(1.D0+APHS*X2
& +BTAS*X2**2+GMS*X2**3)