22.2 Freezing the ordering

An ordering is frozen under the following circumstances:

• The first tree iterator is created using the ordering. See marpa_t_new().
• marpa_o_ambiguity_metric() is successfully called. See marpa_o_ambiguity_metric().
• marpa_o_rank() is successfully called. See marpa_o_rank().

A frozen ordering cannot be changed. There is no way to “unfreeze” an ordering.