push it onto the operand stack. RULE 2: When an operator is encountered in the expression, push it onto the operator stack. RULE 3: When a left parenthesis is encountered in the expression, ignore it.

RULE 1: Scan the expression from left to right. When an operand is encountered, push it onto the operand stack. RULE 2: When an operator is encountered in the expression, push it onto the operator ...