Question #4d4db

1 Answer
Jan 13, 2017

#{{a}}# is a partition of #A#.

Explanation:

Given a set #X#, we say that #Y# is a partition of #X# if

  • Every element of #Y# is a nonempty subset of #X# and
  • Every element of #X# is included in exactly one element of #Y#

If we let #Y = {{a}}# and test to see if #Y# is a partition of #A#, we can see that the first condition is satisfied, as the only element of #Y# is #{a} = A# which is a subset of #A#, and the second condition is satisfied because the only element of #A# is #a#, which is contained in the single element of #Y#.