Find two open sets A and B, such that A is subset of B, A is not equal

[math25]

Find two open sets A and B, such that A is subset of B, A is not equal to B, and m(A)=m(B)

Can I use these two sets?

A=(0,2) B=(0,1) U (1,2)

thanks

 

[Dick]

Almost. Your example has B a subset of A. You want the reverse.

 

[math25]

you are right, thanks