The deque ops are an EXPRESSION STACK: push the left operand, evaluate the right
(a built-in call, whose result lands in special[0]), pop the comparand back into
special[1], compare. Tracking that through the linear decode is enough to recover
what each site tests.
Evidence the model is right, not just plausible:
push vs pop across all 28 stages 1877 vs 1877
files that underflow or end unbalanced 0 of 28
Stage 02 pop.i sites followed by cmp.i 319 / 319
ops immediately before a pop.i call x313, cmp.a x6
isl.conditions() recovers 7563 condition sites disc-wide with 0.0% left as an
unresolved special[N]; 83.2% have a built-in call as the LHS and 99.7% compare
against a plain number. Most-tested: hp_pct_test 1955, unit_state 1257,
unit_relation 796, dist_lt 450, unit_alive 413.
They read as conditions now:
if unit_alive(TCN105) != 1
if hp_pct_test(ADT308, 0) != 1
if dist_lt(ADT308, TCN000, 15000) != 1 (world unit = 1 m, so 15 km)
if unit_state(ADT308) == 1
data/isl-stage02-conditions.txt was a stale artefact with NO generator -- the thing
isl_report.py's docstring complained about. It has one now (isl_report.py
conditions). The calls and phase-ends artefacts both regenerate byte-identical, so
the change is additive.
Recorded rather than glossed: 15 of Stage 02's 965 sites (1.6%) attribute the LHS to
end_coroutine, which returns no value -- the tracker sets special[0] on EVERY call,
so those show a stale value and are wrong, not imprecise. The fix is to set it only
for built-ins that write [phase+164], which the vtable work makes checkable.