7103 Riemann integrable
by EngliSea on 2020-07-16
ᐥA function f defined and bounded on [a,b] is Riemann integrable on [a,b]
if and only if
inf「sup(f(x))Ƨ[a,b]」
= sup「inf(f(x))Ƨ[a,b]」
.
The common value is denoted by f(x)ᐃx「a,b」.ᐥ


inf{U:U=「sup{f(x):x⸤i−1⸥≤x≤x⸤i⸥}·(x⸤i⸥−x⸤i−1⸥) Σi=0,n」}
= sup{L:L=「inf{f(x):x⸤i−1⸥≤x≤x⸤i⸥}·(x⸤i⸥−x⸤i−1⸥) Σi=0,n」}