Quote:
What does ıt mean " $ " symbol .
Do you really need to know ?
The '$' look like an operator in this expression, the only mystery is unary or binary.
By the way, I don't know either whet is the '.', since it is not a multiplication.
You may have to do a deduction, because if you have x values, you have x-1 binary operators.
Since expression look like RPN (Reverse Polish Notation), you don't have to care about operators priority.