M1=I1
M2=I1-I2
I1=M1
I2=M1-M2
O1 = M1 + A0 + A1*I2 + A2*X + A3*T
O2 = M2 + B0 + B1*I2 + B2*X + B3*T
A3=0. m:r,z
B3=0. i:R,R-z
A2=0.08
B2=0.08
A0 =    1.5827    0.0046 <<    8.9   2  2.11 avg of 3 nights.
B0 =    3.5393    0.0051 <<   26.8   2  3.66
A1 =    0.0064    0.0108 <<    1.4   2  0.84
B1 =   0.         0.01   <<   forced to 0.