Async_log_kernel.Ppx_log_syntaxmodule Ppx_log_syntax : module type of Ppx_log_syntaxAsync_log.Ppx_log_syntax.Ppx_log_syntax exists so that people can open Async_log.Ppx_log_syntax to use ppx log, instead of doing a module alias. This is consistent with Monad.Syntax.Let_syntax.