Changes for 1.19.1 (2026-02-02)

  Bug fixes for `abu-parser'.

  * The score of a production of a top-down PCFG might erroneously be zero
    if some of score summands were calculated to non-finite values. The
    calculation of score summands is now improved. They are now equal to
    zeroes instead of non-finite values.

  * Maximum length of an n-gram consisting of terminal or nonterminal
    symbols from a source PCFG was equal to the longest terminal symbol
    sequence consumable by an `rd' or `scn' instruction. As a result of
    this, n-gram length might be less than the length of right-hand side of
    a production from a source PCFG. Now maximum n-gram length is increased
    (up to 8) if it is less than the length of right-hand side of a
    production from a source PCFG.