Function subtract

subtract<T>(left, right): Expression<T>
An expression that subtracts the result of the second expression from the result of the first expression.
```
  var _ = ExpressionFactory;
  //Evaluates to 1.
  var number = _.subtract(_.number(3), _.number(2));
  //Evaluates to (1, 2, 3).
  var point = _.subtract(_.point({x: 3, y: 4, z: 5}), _.number(2));
```
Type Parameters
- T extends string | number | Vector3
Parameters
- left: Expression<T>
  The first expression to evaluate. Should result in a number, point or color.
- right: Expression<number | T>
  The second expression to evaluate. Should result in the same type as left or a number.
Returns Expression<T>
An expression that subtracts the result of the second expression from the result of the first expression. Results in a number, point or color depending on the type of the operands. When a number is used with an other type, the operation is applied to the individual element values and the result is of the other type.