module Operators:sig..end
++, >>, and eps_eval (++) : 'a #Uq_engines.engine ->
       ('a -> 'b #Uq_engines.engine) -> 'b Uq_engines.engineqseq_engine. Use this operator to run engines in
	sequence:
	    e1 ++ (fun r1 -> e2) ++ (fun r2 -> e3) ++ ...
	Here rK is the result of engine eK.
        Change in OCamlnet-3.6.4: ++ is now qseq_engine, and no longer
        seq_engine, and hence it does not support progress reporting anymore.
        Redefine ++ as seq_engine in your own code if you need the old
        behavior.
val (>>) : 'a #Uq_engines.engine ->
       ('a Uq_engines.final_state -> 'b Uq_engines.final_state) ->
       'b Uq_engines.enginefmap_engine. Use this operator to map the
	final value of an engine:
	    e >> (function `Done x -> ... | `Error e -> ... | `Aborted -> ...)
val eps_e : 't Uq_engines.engine_state -> Unixqueue.event_system -> 't Uq_engines.engineepsilon_engine