Final answer:
Yes, according to the Liskov Substitution Principle, postconditions for a method in a subclass should not be stricter than the parent method to maintain the program's correctness.
Step-by-step explanation:
The question relates to the Liskov Substitution Principle (LSP) in object-oriented programming. According to the LSP, postconditions for a method in a subclass should not be stronger than those of the corresponding method in the superclass. In other words, when overriding a method from a parent class, the subclass's method should ensure that the postconditions are at least as permissive as those defined by the parent's method.
So, the answer to the student's question, "Do postconditions for a method need to be at least equal to the parent method when applying the Liskov Substitution Principle?" is yes. The LSP requires that objects of a superclass be replaceable with objects of a subclass without affecting the correctness of the program.