Bourbaki

Exercise 14, § 1

Algebra, VI, p. 32

Show that, in a semi-lattice ordered monoid MM.

inf⁡(xi+yi)≥inf⁡(xi)+inf⁡(yi) \inf(x_i + y_i) \geq \inf(x_i) + \inf(y_i)

for all finite sequences of n terms (xi),(yi)(x_i), (y_i). Deduce the inequalities

(x+y)+≤x++y+,∣x+−y+∣≤∣x−y∣ (x + y)^+ \leq x^+ + y^+ , \quad |x^+ - y^+| \leq |x - y|

in any lattice ordered group.

Solution

No solution has been written yet.

Transcribed from the printed volume. Not translated.