Let x be given.
Assume Hx Hxnonneg.
Apply sqrt_SNo_nonneg_prop1a x Hx Hxnonneg to the current goal.
Let w be given.
Assume Hw Hwnonneg.
Apply SNoS_E2 (SNoLev x) (SNoLev_ordinal x Hx) w Hw to the current goal.
Assume Hw1 Hw2 Hw3 Hw4.
An exact proof term for the current goal is sqrt_SNo_nonneg_prop1 w Hw3 Hwnonneg.