Phase 3 fixed two of the twelve branches of `_inflect_predicate` by hand and
pinned them with a hand-written oracle. The other ten kept handing whole
predicate phrases to single-verb functions, so the same root cause was still
live on **57 of 96** (branch x multi-word predicate) pairs, 9 of 12 branches:
"belongs to" --perfective--> "has belongs toed"
"belongs to" --imperfective--> "is belongs toing"
"belongs to" --past--> "belongs toed"
"is defined as" --future--> "will is defined a"
"contrasts with" --negated--> "does not contrasts with"
Every branch now routes through `morphology.inflect_phrase_head`, which applies
a single-verb inflection to the finite verb and carries tokens 2..n through
byte-identically. Two closed tables were needed because `_base_form` is a
suffix stripper and the head of every copular predicate is a form of BE:
`base_form("is")` returned "i" and `present_participle("is")` returned "iing".
Also fixes predicate-nominal object agreement. `render_step` pluralized the
subject and never the object, so it wrote "all dogs are a mammal". The object
agrees only for a predicate nominal -- a closed set of two -- because a
prepositional object carries its own number and a productive rule would write
"all claims are grounded in evidences".
Measured
--------
tail-mangling pairs 57/96 -> 0/96
g_read_rate (round-trip) 0.0 -> 0.003413 first non-zero in the arc
grammatical_coverage v1 49/49 (2 cases corrected, see below)
english_fluency_ood 117/117 + 39/39 + 13/13 unchanged
discourse_paragraph 12/12 + 6/6 + 5/5 + 1/1 unchanged
zero_code_domain_acquisition 18/18 + 30/30 + 21/21 unchanged
`gram_C14_p01` and `gram_C14_p10` expected "...defined as compound", which is
not English. Corrected, and the old string moved into `reject_surfaces` so the
case now actively rejects what it used to accept. The correction is not my
judgment: the reader independently READS "all molecules are defined as
compounds" and REFUSES the singular form, and that is precisely what took
g_read_rate off zero.
Why the invariant instead of a bigger oracle
--------------------------------------------
A per-branch oracle has to be extended by hand for each new branch, and a
branch added without one is invisible -- which is how eight survived Phase 3.
The pin is structural instead: English marks tense, number and aspect on the
finite verb, so inflection must leave tokens 2..n byte-identical. It needs no
oracle and covers branches nobody has written yet.
It is necessary, not sufficient: "does not contrasts with" preserves its tail
perfectly and is still wrong. `test_do_support_puts_the_head_in_the_bare_
infinitive` is the sufficiency half.
Mutation
--------
baseline 84 pass
inflect_phrase_head applied to the whole phrase 39 FAIL
_IRREGULAR_BASE emptied 2 FAIL
_IRREGULAR_PARTICIPLE auxiliaries removed 2 FAIL
PREDICATIVE_NOMINAL emptied 3 FAIL
PREDICATIVE_NOMINAL widened to every copular predicate 2 FAIL
The last row is the one that matters: the plausible-but-wrong fix -- "pluralize
the object under a plural subject" -- is caught by the mass-noun control.
Not fixed here, deliberately: "has not the following steps" is archaic rather
than wrong, and modernizing it to do-support is a separate judgment call.
[Verification]: smoke 621, deductive 406, lane pins 11/11 unchanged
(grammatical_coverage is not a pinned lane; no pin was edited).
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