Full Idea
The general formal principles of grounding are Transitivity (A«B, B«C/A«C: if A helps ground B and B helps C, then A helps C), Irreflexivity (A«A/absurd: A can't ground itself) and Factivity (A«B/A; A«/B: for grounding both A and B must be the case).
Clarification
A«B means 'A helps ground B' (Fine uses a slightly different symbol)
Gist of Idea
Formal grounding needs transitivity of grounding, no self-grounding, and the existence of both parties
Source
Kit Fine (Some Puzzles of Ground [2010], 4)
Book Reference
-: 'Notre Dame Journal of Formal Logic' [-], p.100