/**
 * A NonterminalExpression
 */
public class AndExp implements BooleanExp {
 private BooleanExp operand1;
 private BooleanExp operand2;
 
 public AndExp(BooleanExp oper1, BooleanExp oper2) {
 operand1 = oper1;
 operand2 = oper2;
 }

 public boolean Evaluate(Context c) {
 return operand1.Evaluate(c) &&
 operand2.Evaluate(c);
 }

 public BooleanExp Copy() {
 return new AndExp(operand1.Copy(), operand2.Copy());
 }

 public BooleanExp Replace(String var, BooleanExp exp) {
 return new AndExp(
 operand1.Replace(var, exp),
 operand2.Replace(var, exp)
 );
 }
}