The paper takes no position on whether our vacuum is false; it supplies the semiclassical machinery (bounce/instanton, Gamma/V = A e^(-B/hbar)) and, here for the first time, its gravitational corrections. Both decay directions relevant to the pipeline appear: decay of a zero-cosmological-constant vacuum into a negative-energy (anti-de Sitter) one, and decay of a positive-energy (de Sitter) vacuum into a zero-energy one, the case applying if we live in the debris of an early-epoch decay.