ICP=4 Milly’s function

$P_{cap}$ = -97.783 x $10^A$

with

$A\quad=\quad2.26\left(\frac{0.371}{S_l\;-\; S_{lr}}\;-\;1\right)^\frac{1}{4}$

where $S_{lr}$ = CP(1)

Restriction: CP(1) ≥ 0.