Machine Learning, Artificial Intelligence, Statistics, Math, Mathematics.
symbol mean — Google Search. (2018). Google.co.kr. Retrieved 31 August 2018, from https://www.google.co.kr/search?q=math+what+does+upside+down+triangle+symbol+mean&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi6pNeyl5fdAhXGzmEKHU0pAukQ_AUICigB&biw=1600&bih=907#imgrc=HtbVWFH2bEP3OM: RuntimeError: expected