class Person {
    Name: string;
    Height: float;
    Age: float;
    Weight: float;
}

calculate_bmi(p: Person {
    age: Age | age > 60,
    height: Height ,
    weight: Weight
    }) : float {
    return weight / (height * height);
}

 main():void {
    eric: Person = new Person{
        Name = 'Eric Morecombe',
        Height = 1.93,
        Age = 65,
        Weight = 100
    };
    print(calculate_bmi(eric));
}