Migration to OH2 - Error in rule

Hi, i get following error in one of my rules, since i migratet to OH2:

2017-02-13 11:44:01.569 [ERROR] [.script.engine.ScriptExecutionThread] - Rule 'Soll-Temp-Heizung dämpfen - wenn Unterschied 1h und 24h Aussentemp zu groß': An error occured during the script execution: The name '<XBinaryOperationImplCustom> && <XBinaryOperationImplCustom>' cannot be resolved to an item or type.

Her is my rule:

rule "Soll-Temp-Heizung dämpfen - wenn Unterschied 1h und 24h Aussentemp zu groß"
    when
		Item HeatPump_Temperature_4 received update
    then
		HeatPump_Unterschied_1h_24h.postUpdate(HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType)
		if (HeatPump_enable_heating.state==ON) {
			if (HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType > -1.5) {
				if (HeatPump_adapt_heating.state as DecimalType != 0) {
					sendCommand(HeatPump_adapt_heating, 0)
				}
			}
			if ((HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType <= -2.0) && (HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType > -4.5)) {
				if (HeatPump_adapt_heating.state as DecimalType != -0.5) {
					sendCommand(HeatPump_adapt_heating, -0.5)
				}
			}
			if ((HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType <= -5.0) && (HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType > -7.5)) {
				if (HeatPump_adapt_heating.state as DecimalType != -1.0) {
					sendCommand(HeatPump_adapt_heating, -1.0)
				}
			}
			if ((HeatPump_Temperature_4.state as DecimalType - HeatPump_Temperature_5.state as DecimalType <= -8.0) {
				if (HeatPump_adapt_heating.state as DecimalType != -1.5) {
					sendCommand(HeatPump_adapt_heating, -1.5)
				}
			}
		}
end

Is this really needed? I think this are all of type Number? The problem is somewhere near the && operator. :wink: