# Math [Obj,Double]

### Description
Executes a free math expression on the values of the second column.

Warning: this block can fail if the expression is invalid (e.g. referring to a non available mathematical function),
or if the expressions computes to invalid results (e.g. division by zero).

### Input
- `A [OBJ,DOUBLE]`: a list of pairs

### Output
- `RESULT [OBJ,DOUBLE]`: result of the operation
### Parameters
- `Expression`: the mathematical expression to compute
  - use `$A` to refer to the values comings from input `A`
  - arithmetic operators and common mathematical functions can be used
  - the expression is evaluated by the database engine. See [MonetDB Functions and Operators](https://www.monetdb.org/Documentation/SQLReference/FunctionsAndOperators/MathematicalFunctionsOperators) for a full list of functions and operators available.