Is Plook at Problem14.12 of chapter3 of "Aliprantis-Burkinshaw-Principles of real analysis-3ed.1998" ; 12. Let A be the collection of all measurable subsets of X of finite measure. That is, A = {B in X: m(XA) < oo}. a connected set for. Show that A is a set X withsemiring. b. Define a $\sigma$-algebra Prelation ~ on A by B ~ C if m(XB \Delta C) and a measure function m= 0. Show that ~ is an equivalence relation on it to [0A. c. Let D denote the set of ail equivalence classes of A. For B in A let B* denote the equivalence class of B in D. Now for B*,$\infty$] when P C* in D define d(XB*, C*) is equiped with meter= m(B \Delta C). Show that d, is well defined and that for every A(D,B in P d) is a complete metric space. (XFor this part, see also Exercise [3] of Section [31].)
Now let m be lebesgu measure on Real numbers and X be a subset of Real line, is $d(A,B)=m(A \Delta B)$(D,d) a connected space with topology induced with meter d?