I think you're a bit too narrow in your definition. If an abstraction specifies ...

		AnimalMuppet on March 20, 2020 \| parent \| context \| favorite \| on: A principled approach to system design and program... I think you're a bit too narrow in your definition. If an abstraction specifies properties, but I have to care about more than those properties to be able to use the abstraction, then the abstraction leaked. Performance can be one of those things I have to care about.