  We give a procedure that can be used to automatically satisfy invariants of a
certain shape. These invariants may be written with the operations
intersection, composition and converse over binary relations, and equality over
these operations. We call these invariants \tr{}s that we interpret over
graphs. For questions stated through sets of these sentences, this paper gives
a semi-decision procedure we call graph saturation. It decides entailment over
these \tr{}s, inspired on graph rewriting. We prove correctness of the
procedure. Moreover, we show the corresponding decision problem to be
undecidable. This confirms a conjecture previously stated by the author.
