user> (condp some [1 2 3 4]
             #{5}  :>> inc
             :the-default-value)

:the-default-value

user> (some #{5} [1 2 3 4])
nil

user> (condp some [1 2 3 4] #{1}  :>> inc :the-default-value)
2

user> (some #{1} [1 2 3 4])
1

(some #{0 6 7} [1 2 3 4])

user> (some #{4 5 9} [1 2 3 4])
4

user> (dec 4)
3