Also I use the definition symbol "≡" to outline features. Most basic scenario is f(x) ≡ y. I am applying it to point out a romance to search out sums in lieu of stating it as being the sum that we're deriving nonetheless it can be employed to state equivalence. https://johnathanxukzq.newsbloger.com/37054872/the-best-side-of-por-qué-es-bueno-leer-el-tarot