List of variables of an algebraic expressions: algvar

### 6.59.4 List of variables of an algebraic expressions: algvar

The algvar command finds the symbolic variable names in an expression, but orders them.

- algvar takes one argument:
  expr, an expression.
- algvar(expr) returns the list of the symbolic variable names used in expr, ordered by the algebraic extensions required to build expr.

Examples.

- Input:
  algvar(y+x*sqrt(z))
  Output:

  ⎡ ⎣ | ⎡ ⎣ | y,x | ⎤ ⎦ | , | ⎡ ⎣ | z | ⎤ ⎦ | ⎤ ⎦

- Input:
  algvar(y*sqrt(x)*sqrt(z))
  Output:

  ⎡ ⎢ ⎢ ⎣ |
  y
  z
  x
  | ⎤ ⎥ ⎥ ⎦

- Input:
  algvar(y*sqrt(x*z))
  Output:

  ⎡ ⎣ | ⎡ ⎣ | y | ⎤ ⎦ | , | ⎡ ⎣ | x,z | ⎤ ⎦ | ⎤ ⎦

- Input:
  algvar(y+x*sqrt(z)+y*sin(x))
  Output:

  ⎡ ⎣ | ⎡ ⎣ | y,x,sinx | ⎤ ⎦ | , | ⎡ ⎣ | z | ⎤ ⎦ | ⎤ ⎦