A theory, graphical notation, mathematical calculus and implementation for finding whether two given expressions can, at execution time, denote references attached to the same object. Intended as the basis for a comprehensive solution to the "frame problem" and as an alternative (for the specific issue of determining aliases) to separation logic, shape analysis, ownership types and dynamic frames. 1 Dynamic aliasing You have, most certainly, read Homer. I have not (too much blood), but then I listen to Offenbach a lot, so we share some knowledge: we both understand that "the beautiful daughter of Leda and the swan", "poor Menelaus's spouse" and "P