It is at least head-strict, and perhaps more. 47 48 * `C(s)` -- a ''call-demand'', when placed on a binder `x`, indicates that the value is a function, which is always called and its result is used according to the demand `s`. 49 50 51Absence demands 52 53 * `A` -- when placed on a binder `x` it means that `x` is definitely unused. 54 55 * `U` -- the value is used on some execution path.