1. Push “(“ onto STACK, and add “)” to the end of X.
2. Scan X from left to right and REPEAT Steps3 to 6 for each element of X UNTIL the STACK is empty.
3. If an operand is encountered, add it to Y.
4. If a left parenthesis is encountered, push it onto STACK.
5. If an operator is encountered, then:
(a) Repeatedly pop from STACK and add to Y each operator (on the top of STACK) which has the same precedence as or higher precedence than operator.
(b) Add operator to STACK.
/* End of If structure */
6. If a right parenthesis is encountered, then:
(a) Repeatedly pop from STACK and add to Y each operator (on the top of STACK) until a left Parenthesis is encountered.
(b) Remove the left parenthesis. (Do not add the left parenthesis to Y).
/* End of If structure */
7. END.
