Usual functions

### 2.16.2 Usual functions

- `max` takes as argument two real numbers and returns their maximum,
- `min` takes as argument two real numbers and returns their minimum,
- `abs` takes as argument a complex number and returns the modulus of the complex parameter (the absolute value if the complex is real),
- `sign` takes as argument a real number and returns its sign (+1 if it is positive, 0 if it is null, and -1 if it is negative),
- `floor` (or `iPart`) takes as argument a real number r, and returns the largest integer ≤ r,
- `round` takes as argument a real number and returns it’s nearest integer,
- `ceil` or `ceiling` takes as argument a real number and returns the smallest integer ≥ r
- `frac` (or `fPart`) takes as argument a real number and returns its fractionnal part,
- `trunc` takes as argument a real number and returns the integer equal to the real without its fractionnal part,
- `id` is the identity function,
- `sq` is the square function,
- `sqrt` is the squareroot function,
- `exp` is the exponential function,
- `log` or `ln` is the natural logarithm function,
- `log10` is the base-10 logarithm function,
- `logb` is the logarithm function where the second argument is the basis of the logarithm: `logb(7,10)=log10(7)=log(7)/log(10)`,
- `sin` (resp. `cos`, `tan`) is the sinus function, cosinus function, tangent function,
- `cot, sec, csc` are the cotangeant, secant, cosecant function
- `asin` (or `arcsin`), `acos` (or `arccos`), `atan` (or `arctan`), `acot, asec, acsc` are the inverse trigonometric functions (see section 2.21.1 for more info on trigonometric functions)
- `sinh` (resp. `cosh`, `tanh`) is the hyperbolic sinus function, cosinus function, tangent function,
- `asinh` or `arcsinh` (resp `acosh` or `arccosh`, `atanh` or `arctanh`) is the inverse function of `sinh` (resp `cosh`, `tanh`)