method neq = self#prim2 (fun t -> (self#at t)#neq)
method max = self#prim2 (fun t -> (self#at t)#max)
method min = self#prim2 (fun t -> (self#at t)#min)
+ method shl = self#prim2 (fun t -> (self#at t)#shl)
+ method shr = self#prim2 (fun t -> (self#at t)#shr)
method delay : signal_type -> signal_type =
fun (s : signal_type) ->