14 | | Assume for all parents `P`, `Q`, `P.register_coercion(Q)` will be done in `P.__init__()`, but not later. Assume that parent~~ `R` to parent~~ `S` exist at time `t_0`, but there is no path from `R` to `S` in the coerce digraph at time `t_0`. Assume that between time `t_0` and time `t_1`, `.register_embedding()` has never been called. Then, there is no path from `R` to `S` in the coerce digraph at time `t_1`. |

| 14 | Assume for all parents `P`, `Q`, `P.register_coercion(Q)` will be done in `P.__init__()`, but not later. Assume that parents `R` and `S` exist at time `t_0`, but there is no path from `R` to `S` in the coerce digraph at time `t_0`. Assume that between time `t_0` and time `t_1`, `.register_embedding()` has never been called. Then, there is no path from `R` to `S` in the coerce digraph at time `t_1`. |