+ | (EApp ((EVar "dnsAFSDB", _), e), _) =>
+ Option.map AFSDB (Env.string e)
+ | (EApp ((EApp ((EApp ((EApp ((EApp ((EVar "dnsSRV", _), e1), _), e2), _), e3), _), e4), _), e5), _) =>
+ (case (srv_host e1, Env.int e2, Env.int e3, Env.int e4, Env.string e5) of
+ (SOME v1, SOME v2, SOME v3, SOME v4, SOME v5) => SOME (SRV (v1, v2, v3, v4, v5))
+ | _ => NONE)