- spec settles 9b's three forks: SQL/Cypher layer superseded as the
program surface (design history + wo-db engine-semantics reference);
comprehension syntax desugared at compile time (no function values);
System.Linq = operator vocabulary + edge cases, PostgreSQL = execution
+ integrity vocabulary (both references surveyed 2026-08-15)
- aggregate semantics normative: count/sum total 0 on empty, avg/min/max
are ?T with nil (empty is data, not a fault); nil skipped; sum wraps
like language arithmetic; GroupBy lowers as group-and-reduce
(AggregateBy shape), transition/finalize ABI from nodeAgg
- relations: ref = FK with direct-index-probe check (nil passes,
unchanged-key skips), backlink = secondary-index scan, delete is
restrict-only; nil never joins, nil is a legal group key
- lowering: the compiler is the planner — queries become bytecode loops
over cursor/group builtins, longest-prefix index selection, no plan
tree, no SQL text in the image (disassembly-provable)
- plan: 6 tasks gated by a new docs/examples/employee sample
(Department/Employee, @unique, composite index, ref/backlink,
GroupBy report mode) with its own acceptance script + crash step;
blocked on iteration 9's engine plan
- story 09b + status board updated; 02-wo-language.md carries the
supersession note
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>