There is also the in function:
start = [1, 3, 4, 6]
start_site = 1:5
in_start_site = in(start_site) # in(...) returns a function
in_start_site.(start) # [true, true, true, false]
in(collection) returns a function that tests if something is in collection. You can also write this in one line:
in(start).(start_site)