タイマー型とそのプリミティブ関数を提供．

signature TIMER =
sig
  type cpu_timer
  type real_timer
  val checkCPUTimer : cpu_timer -> {usr : Time.time, sys : Time.time}
  val checkCPUTimes
    : cpu_timer
Ψ-> {nongc : {usr : Time.time, sys : Time.time}, gc : {usr : Time.time, sys : Time.time}}
  val checkGCTime : cpu_timer -> Time.time
  val checkRealTimer : real_timer -> Time.time
  val startCPUTimer : unit -> cpu_timer
  val startRealTimer : unit -> real_timer
  val totalCPUTimer : unit -> cpu_timer
  val totalRealTimer : unit -> real_timer
end