update_modified_movement_power_effect

update_modified_movement_power_effect = {
	if = {
		limit = {
			exists = var:movement_power_increased_scheme
		}
		change_variable = {
			name = movement_power_increased_scheme
			add = movement_power_increased_scheme_decay_value
		}
		if = {
			limit = { var:movement_power_increased_scheme <= 0 }
			remove_variable = movement_power_increased_scheme
		}
	}
	if = {
		limit = {
			exists = var:movement_power_decreased_scheme
		}
		change_variable = {
			name = movement_power_decreased_scheme
			add = movement_power_decreased_scheme_decay_value
		}
		if = {
			limit = { var:movement_power_decreased_scheme >= 0 }
			remove_variable = movement_power_decreased_scheme
		}
	}
	if = {
		limit = {
			exists = var:movement_power_increased_event
		}
		change_variable = {
			name = movement_power_increased_event
			add = movement_power_increased_event_decay_value
		}
		if = {
			limit = { var:movement_power_increased_event <= 0 }
			remove_variable = movement_power_increased_event
		}
	}
	if = {
		limit = {
			exists = var:movement_power_decreased_event
		}
		change_variable = {
			name = movement_power_decreased_event
			add = movement_power_decreased_event_decay_value
		}
		if = {
			limit = { var:movement_power_decreased_event >= 0 }
			remove_variable = movement_power_decreased_event
		}
	}
	if = {
		limit = {
			exists = var:movement_power_increased_petition
		}
		change_variable = {
			name = movement_power_increased_petition
			add = movement_power_increased_petition_decay_value
		}
		if = {
			limit = { var:movement_power_increased_petition <= 0 }
			remove_variable = movement_power_increased_petition
		}
	}
	if = {
		limit = {
			exists = var:movement_power_decreased_petition
		}
		change_variable = {
			name = movement_power_decreased_petition
			add = movement_power_decreased_petition_decay_value
		}
		if = {
			limit = { var:movement_power_decreased_petition >= 0 }
			remove_variable = movement_power_decreased_petition
		}
	}
}

As written in game/common/scripted_effects/10_dlc_tgp_scripted_effects.txt.