Static and runtime types: Correct Solution

Given the following type declarations:

public class Entrad {
    public Entrad remian(Entrad te) {
        return te;
    }
}

public class Tendgel extends Entrad {
    public Entrad remian(Entrad te) {
        return this;
    }
}

public class Plalstek extends Entrad {
    public Entrad remian(Entrad te) {
        return new Tendgel();
    }
}

...and given the following setup code:

Tendgel foo = new Tendgel();
Entrad bar = new Plalstek();

Part 1

Draw an AST for the following expression, labeling the static type (a.k.a. compile-time type) of each node in the tree:

foo.remian(foo.remian(bar))

(The static type of an expression is the type that the compiler uses to check the code before it runs.)

Solution

Part 2

Draw an AST for the same expression, this time labeling the runtime type of each node in the tree.

(The runtime type of an expression is the type of the actual value that appears when the code runs.)

Solution

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