Sequence Control Within Expressions
4. Semantics for ExpressionsSemantics determine the order of expression in which they are evaluated.a) Evaluation of Prefix ExpressionIf Pis an expression evaluate using stacki) If the next item in Pis an operator, push it on the stack. set the arguments count to be number of operands needed by operator.(if number is n, operator is nary operator).ii) If the next item in Pis an operand, push it on the stackiii) If the top n entries in the stack are operand entries needed for the last nary operator on the stack, apply the operator on those operands. Replace the operator and its n operands by the result of applying that operation on the n operands.b) Evaluation of Postfix ExpressionIf Pis an expression evaluate using stacki) If the next item in Pis an operand, push it on the stack. ii) If the next item in Pis an nary operator, its n arguments must be top n items on the stack. Replace these n items by the result of applying this operation using then items as arguments. Sequence Control Within Expressions
c) Evaluation of Infix ExpressionInfix notation is common but its use in expression cause the problems:i) Infix notation is suitable only for binary operations. A language cannot use Share with your friends: 
