Modifies the value stored in a variable by adding it a value.
Parameters:
symbol -
A symbol object identifying a variable in the current context. The
variable must contain a numeric value.
value -
A numeric object represeting the value to be added to
symbol.
Returns:
The new value of the variable.
Modifies the contents of the variable identified by
symbol by adding
value to the value it had previously stored.
The variable binded to symbol is expected to
contain a numeric object.
