more from Stephen Yablo

### Single Idea 18999

#### [catalogued under 4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology]

Full Idea

The principle of Supplementation says that y is properly part of x, only if a z exists that 'makes up the difference' between them. [note: that is, z is disjoint from y and sums with y to form x]

Gist of Idea

y is only a proper part of x if there is a z which 'makes up the difference' between them

Source

Stephen Yablo (Aboutness [2014], 03.2)

Book Reference

Yablo,Stephen: 'Aboutness' [Princeton 2014], p.47