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4. Rabby Computer Inc agreed to design a networking system for Pendulum Publishing Ltd. The contract called for Pendulum to pay $50 000 after Rabby completed its performance. However, when Rabby finished designing the system, Pendulum stated that it could not afford to pay that amount of money in cash. Pendulum therefore asked Rabby if it would agree to discharge the contract upon receipt of $35 000. Although Rabby initially agreed to the proposal, it later insisted upon full payment. It did so before it actually received any money from Pendulum. Is Pendulum entitled to have the contract discharged if it pays $35 000? Would your answer be different if Rabby had promised under seal that he would discharge the contract upon receipt of $35 000? Would your answer be different if Rabby had initially agreed to discharge the contract in exchange for $35 000 plus a set of encyclope- dias from Pendulum? Explain your answers