Given the set s = { ∅, d, { d }, { { d } }, { { { d } } } }. determine the cardinality of the power set of s list the elements of the power set. to save writing, let v = ∅, w = d, x = { d }, y = { { d } }, and z = { { { d } } }.

Respuesta :

[tex]S=\{\varnothing,d,\{d\},\{\{d\}\},\{\{\{d\}\}\}\}=\{v,w,x,y,z\}[/tex]

A set containing [tex]n[/tex] elements has a power set containing [tex]2^n[/tex] elements; here, [tex]|S|=5[/tex] so [tex]|\mathscr P(S)|=2^5=32[/tex].

The elements of the power set are all possible combinations of up to 5 of the total 5 elements to choose from:

0 choices (1): [tex]v[/tex] (since [tex]v=\varnothing[/tex])

1choice (5): [tex]\{v\},\{w\},\{x\},\{y\},\{z\}[/tex]

2 choices (10): [tex]\{v,w\},\{v,x\},\{v,y\},\{v,z\},\{w,x\},\{w,y\},\{w,z\},\{x,y\},\{x,z\},\{y,z\}[/tex]

3 choices (10): [tex]\{v,w,x\},\{v,w,y\},\{v,w,z\}[/tex] and so on

4 choices (5); [tex]\{v,w,x,y\},\{v,w,x,z\}[/tex] and so on

5 choices (1): [tex]\{v,w,x,y,z\}[/tex]

(1 + 5 + 10 + 10 + 5 + 1 = 32)