True or False?
The recursive definition of the set S={1,5,9,13,17,…} is 1∈S;x∈S→x+4∈S.

Question

True or False?
The recursive definition of the set S={1,5,9,13,17,…} is 1∈S;x∈S→x+4∈S.

alprincenofl · Answer

Screenshot: http://prntscr.com/57m71r

anonymous · Answer

false

anonymous · Answer

False

alprincenofl · Answer

Why it's false?
I think it's True.
Both of "x" and "4" is a part of the set "S" so:
x+4=??
Replace any number of the set with "x":
1+4=5
or
5+4=9
or etc
all belong to the set "S" so it's True
@nbandy0128 @Saquara

alprincenofl · Answer

@e.mccormick @jim_thompson5910 
Can anyone please confirm the answer?

jim_thompson5910 · Answer

That looks right, but I'm not familiar with this notation. So I'd get a 2nd opinion.

alprincenofl · Answer

@jim_thompson5910
What's your opinion please, true or false?
I am confused

jim_thompson5910 · Answer

it looks true, but again not 100% sure