Bourbaki

Exercise 1, § 8

General Topology, IV

If xx and yy are real, we have

[x+y]=[x]+[y]+εwhere ε=0 or ε=1, [x + y] = [x] + [y] + \varepsilon \quad \text{where } \varepsilon = 0 \text{ or } \varepsilon = 1,
[x−y]=[x]−[y]−εwhere ε=0 or ε=1, [x - y] = [x] - [y] - \varepsilon \quad \text{where } \varepsilon = 0 \text{ or } \varepsilon = 1,
[x]+[x+y]+[y]⩽[2x]+[2y], [x] + [x + y] + [y] \leqslant [2x] + [2y],
[x]+[x+1n]+[x+2n]+⋯+[x+n−1n]=[nx], [x] + \left[ x + \frac{1}{n} \right] + \left[ x + \frac{2}{n} \right] + \cdots + \left[ x + \frac{n-1}{n} \right] = [nx],
[[nx]n]=[x] \left[ \frac{[nx]}{n} \right] = [x]
for any integer n>0n > 0.

Solution

No solution has been written yet.

Transcribed from the printed volume. Not translated.