Develop a circuit diagram for the following, using IEC systems: A 230V relay coil R1 has on/off control provided by four push button switches S1, S2, S3, and S4. Both S1 and $2 must be pushed simultaneously to turn on relay R1, and either S3 or S4 can be pushed to turn off R1. When the relay is de-energised, Lamp L2 is to be off and Lamp L1 is to be on. The relay has two normally open and two normally closed contacts. When either of the "on" pushbuttons is pressed, the relay will be held in the energized condition by a relay contact. The circuit is protected by a circuit breaker.