Show every subsequence of a subsequence of a given sequence is itselfa subsequence of the given sequence. Hint: Define subsequences asin (3) of Definition 11.1 g

Respuesta :

Answer: Suppose that [tex]S_{n}[/tex],  [tex]K_{n}[/tex] and [tex]A_{n}[/tex] are all sequences, also suppose that  [tex]A_{n}[/tex] ⊂ [tex]K_{n}[/tex] ⊂ [tex]S_{n}[/tex]  ∀ [tex]n[/tex] ∈ [tex]Z^{+}[/tex]. This implies that [tex]A_{n}[/tex] ⊂ [tex]S_{n}[/tex] as required. 

Step-by-step explanation:

If you suppose that [tex]S_{n}[/tex],  [tex]K_{n}[/tex] and [tex]A_{n}[/tex]  are all representing three sequences respectively, and you also suppose that  [tex]A_{n}[/tex] is a subset (in other words subsequence) of [tex]K_{n}[/tex] and [tex]K_{n}[/tex]  is a subset (in other words subsequence) of [tex]S_{n}[/tex], where n takes its values from the set of positive integers. We can safely say that [tex]A_{n}[/tex] is a subsequence of [tex]S_{n}[/tex] and this can demosnstrated mathematically as follows:

Suppose that [tex]S_{n}[/tex],  [tex]K_{n}[/tex] and [tex]A_{n}[/tex] are all sequences, also suppose that  [tex]A_{n}[/tex] ⊂ [tex]K_{n}[/tex] ⊂ [tex]S_{n}[/tex]  ∀ [tex]n[/tex] ∈ [tex]Z^{+}[/tex]. This implies that [tex]A_{n}[/tex] ⊂ [tex]S_{n}[/tex] as required.