module Seq.Exceptionless:sig..end
val hd : 'a Seq.t -> 'a optionval tl : 'a Seq.t -> 'a Seq.t optionval first : 'a Seq.t -> 'a optionval last : 'a Seq.t -> 'a optionval at : 'a Seq.t -> int -> 'a optionval reduce : ('a -> 'a -> 'a) -> 'a Seq.t -> 'a optionval max : 'a Seq.t -> 'a optionval min : 'a Seq.t -> 'a optionval combine : 'a Seq.t -> 'b Seq.t -> ('a * 'b) Seq.t option