mrom_yes_observer_impl
=============================

An observer for layers that use strength\_patterns.  Output is based on the
variable threshold rule of MROM.  If the layer's current\_time is before
`check_time`, the threshold is `threshold_high`.  Otherwise, calculate the
summed activity at `check_time` and compare to `check_threshold`.  If the
summed activity is greater than `check_threshold`, the threshold is
`threshold_low`, otherwise `threshold_high`.  If any current element of the
state pattern is greater than the threshold, return "yes", else return "?".

Parameter
---------

Is a parameter\_client:
	parameter	default\_value
	threshold_low	0
	threshold_high	0
	check_time	0
	check_threshold	0