Renunciation when performance is due amounts to breach, with all the consequences thereof.1 The party in default can not, after renunciation during performance, which has been treated by the adversary party as a breach amounting to a discharge, elect to treat the contract as still in force.2 After a contractor has treated a contract as discharged on notice from the adversary party to stop work, a subsequent notice by such party several months later, to resume performance, does not prevent such prior notice from operating as a discharge,3 especially if the contractor has so altered his position that it is impracticable for him to resume performance.4 Refusal to perform waives the duty of the adversary party to make a subsequent tender.5