i ∈ { i, h, o, p }
That says:
"i" is one of these 4 things: i, h, o, or p. True or false?
2 ∈ { -2, 5, 8, 9 }
That says:
"2" is one of these 4 things: -2, 5, 8, or 9. True or false?
{ e, h, a, n } = { a, h, e, n }
That says:
Every one of these e,h,a,n is also one of these: a,h,e,n and also
every one of these a,h,e,n is also one of these: e,h,a,n. True or false?
4 ∈ { {3}, {4}, {5} }
That says:
"4" is one of these {3}, {4}, {5}. True or false?
10 ∉ { 2, 4, 6, 8, 10, 12 }
That says 10 is NOT one of these: 2, 4, 6, 8, 10, 12. True or false?
Now answer them.
Edwin