the first additional rule of natural deduction is if there's a contradiction and you didn't make a mistake, you're clearly just making stuff up and it's fine if you keep going because whatever you conclude you can't bring it back to the real world.
"As president, the 63-year-old held a referendum in 2015 on constitutional changes that turned the country into a parliamentary republic and shifted powers from the president to the prime minister. Armenians supported the changes and Mr Sargsyan gave a public pledge not to become premier himself. Yet after Mr Sargsyan stepped down as president earlier this year, having served the maximum permitted two terms, the country’s ruling Republican party elected him to the prime minister’s role starting last week. "