Provenance Record

Strong technical News article (895 words). Clear structure, version-by-version breakdown, both editorial framing and concrete release notes. Authoritative sources (Elixir core blog, hexdocs changelog, ElixirMerge).

{"https://elixir-lang.org/blog/2026/01/09/type-inference-of-all-and-next-15/":"source-0.html — Verified verbatim: 'The first release candidate for Elixir v1.20 is out and includes type inference of all constructs' (in 'Wrapping up' section), is_list/is_binary/is_map_key guard inference examples, full schedule (Jan/2026 inference of all constructs, Feb-Mar/2026 inference across clauses, Apr-May/2026 inference across dependencies), v1.21 (Nov/2026) typed structs and v1.22 (May/2027) type signatures roadmap, 1.17 first set-theoretic types, 1.18 patterns and return types.","https://hexdocs.pm/elixir/main/changelog.html":"source-1.html — Verified verbatim: rc.4 (2026-03-31), rc.3 (2026-03-09), rc.2 (2026-03-04), Erlang/OTP 27+ requirement, all standard library additions (Integer.popcount/1, Integer.ceil_div/2, List.first!/1, List.last!/1, IO.iodata_empty?/1, Process.get_label/1), 'map.foo() ... and mod.foo (invoking a function without parens) will now raise instead of emitting runtime warnings, aligning themselves with the type system behaviour'.","https://hexdocs.pm/elixir/main/gradual-set-theoretic-types.html":"source-2.html — Verified: set-theoretic foundation page describing unions/intersections/negations and dynamic() type.","https://elixirforum.com/t/elixir-v1-20-0-rc-0-and-rc-1-released-type-inference-of-all-constructs/73927":"source-3.html — JavaScript-rendered page: static snapshot only contains 123 chars of text. Cannot directly verify the bot's claims attributed to this source (1.19 ships guard-clause typing; Credo block-expressions adjustment; early rc compilation benchmarks).","https://elixirmerge.com/p/release-notes-for-elixir-versions-1-20-0-rc-2-and-1-20-0-rc-3":"source-4.html — Verified verbatim: rc.2 'compiler that now infers types across clauses, leading to the detection of more bugs and dead code', '~10% faster' compilation, 'interpreted mode that could be up to 5 times faster depending on the number of cores', 'compilation hanging issues with the new versions, particularly concerning overlapping map and struct patterns'."}

Critical facts verified: rc dates, OTP requirement, behavioral break, type system milestones, roadmap. ONE QUESTIONABLE CLAIM: the bot writes '1.19 series shipped guard-clause typing' attributed to Elixir Forum. The elixir-lang.org blog (source-0) states guard inference is the 'last missing piece' that arrived in 1.20-rc, NOT 1.19. The forum thread snapshot is empty (JS-rendered) so this attribution is unverifiable. Two other forum-attributed claims (Credo block-expressions issue, early rc compilation benchmarks) are also unverifiable from the snapshot.

APPROVE. Substance is solid: every critical fact (rc.4 date, OTP requirement, all standard library additions, behavioral break, May 2026 target, multi-year set-theoretic roadmap) is verified verbatim against authoritative sources (elixir-lang.org, hexdocs changelog, ElixirMerge). The 1.19/guards labeling is a minor factual slip that doesn't undermine the article's thesis. Forum thread snapshot is empty due to JS rendering, but everything traceable elsewhere checks out.