Calculator+ Variable, Equation, Function
+ Basic operators: +, -, * (multiply), / (divide)
+ Exponentiation operator: ^
+ Negation: unary -
+ Assignment: =
+ Square root function: sqrt()
+ Absolute value function: abs()
+ Log functions: log(), log2(), ln(), exp()
+ Transcendental functions: sin(), cos(), tan(), asin(), acos(), atan(), sinh(), cosh(), tanh(), asinh(), acosh(), atanh()
+ Rounding functions: ceil(), floor(), round(), trunk()
+ Angular conversion functions: dtor(), rtod()
+ Constants: pi