#define G1 4 //2kW
#define G2 5 //3kW
#define G3 6 //5kW
#define G4 7 //7kW
#define Zul 8 //<10kW

bool G1x,G2x,G3x,G4x;

void setup() {
pinMode(G1, INPUT_PULLUP);
pinMode(G2, INPUT_PULLUP);
pinMode(G3, INPUT_PULLUP);
pinMode(G4, INPUT_PULLUP);
pinMode(Zul, OUTPUT);
}

void loop() {
G1x = !digitalRead(G1);
G2x = !digitalRead(G2);
G3x = !digitalRead(G3);
G4x = !digitalRead(G4);
if((G1x and G2x)or(G1x and G3x and G4x))
digitalWrite(Zul, LOW);
else
digitalWrite(Zul, HIGH);
}