rewrite [← trunc, ← ulp_trunc npos, ← next]
case h.h₂
x y n : ℕ
npos : 0 < n
h : trunc n x ≤ y
k : y < next n (trunc n x)
ulp_eq : ulp n x = ulp n y
⊢ y < x / ulp n x * ulp n x + ulp n x
case h.h₂
x y n : ℕ
npos : 0 < n
h : trunc n x ≤ y
k : y < next n (trunc n x)
ulp_eq : ulp n x = ulp n y
⊢ y < next n (trunc n x)