EM Realization: Admissible/Barwise Adapter Layer #
This file contains the theorems that connect the EM template-theory machinery
(from Realization.lean) to the admissible-fragment infrastructure. These are
the _of_fragment, _of_fullFragment, and _of_compact endpoints that take
FiniteCompactFragment, FullBarwiseFragment, or bare compactness hypotheses.
Separated from Realization.lean so that the Countable import bundle can
import the core EM machinery without transitively pulling in admissible-fragment
infrastructure. The adapter layer lives in the Admissible bundle instead.
Model of templateTheoryOn via Barwise compactness #
Abstract Barwise wrapper for the restricted template theory.
Indiscernible specialization of templateTheoryOn_model_of_fragment.
Sequence-indexed adapter wrappers #
Abstract Barwise wrapper for templateTheoryOfSeq.
Full-Barwise-fragment specialization.
Sequence-indexed model_of_fragment for indiscernible source.
Caller-ready EM-realization from a full Barwise fragment.
Caller-ready EM-realization from a full Barwise fragment, under restricted indiscernibility.
Stretching along an arbitrary target order #
These theorems package the existing templateTheoryOfSeq pipeline into
caller-ready form: from an indiscernible template they produce a target
L[[J]]-structure N whose constants satisfy the template on formulas in
Set.range s (the countable family named by the enumeration s). The
target order J is an arbitrary linear order — including uncountable
target orders, which is where Morley–Hanf cardinality amplification lives.
Two forms are provided:
stretch_restricted_of_fullFragment/_of_compactuseSentenceω.Realize (templateSentence φ t) Nas the conclusion — this is the form the template theory literally delivers.stretch_restricted_sequence_of_fullFragment/_of_compactproduce an explicitb : J → Nsequence and concludeφ.Realize Empty.elim (b ∘ t) ↔ h.template.truth φ, via the bridgerealize_templateSentence_of_structure.
Scope: these theorems do NOT claim full IsLomega1omegaIndiscernible for
any extracted sequence — that would require enumerating all Lω₁ω formulas,
which is not currently formalized. They DO allow uncountable J, which is
what cardinality amplification for MorleyHanfTransfer eventually needs;
the residual step is extracting an indiscernible source sequence of length
I ≥ ℶ_ω₁ from a large model (the Erdős–Rado half, not addressed here).
EM stretching along an arbitrary target order (full Barwise fragment).
Given an Lω₁ω-indiscernible sequence a : I → M over an infinite linear order
I, a formula enumeration s : ℕ → Σ n, L.BoundedFormulaω Empty n, and a
linear order J with a full Barwise fragment for L[[J]], there
exists a target L[[J]]-structure N such that for every index i : ℕ and
every strictly-increasing tuple t : Fin (s i).1 ↪o J, the realization of
templateSentence (s i).2 t in N matches the truth value of (s i).2 in
the source template.
The conclusion is quantified over i : ℕ (equivalently, over formulas in
Set.range s) — this is restricted indiscernibility. Full Lω₁ω-indiscernibility
of the J-indexed constants would additionally require a countable enumeration
of all Lω₁ω formulas.
Generalized realize_templateSentence.
Like realize_templateSentence (InfinitaryLogic/Methods/EM/Realization.lean:97),
but takes an arbitrary [L[[J]].Structure N] instead of requiring the
L[[J]]-structure to be built from a specific σ : J → M via
constantsOn.structure σ. The L-structure on N is derived from the
L[[J]]-structure via the canonical reduct along lhomWithConstants L J.
The right-hand side realizes φ on the sequence fun i => b (t i), where
b j is the closed-term realization of the constant symbol Sum.inr j
(i.e., the interpretation of the J-indexed constant in the given
L[[J]]-structure on N).
EM stretching along an arbitrary target order — sequence form (full Barwise fragment).
Corollary of stretch_restricted_of_fullFragment via the bridge
realize_templateSentence_of_structure: produces an explicit b : J → N
sequence such that for every i : ℕ and every strictly-increasing tuple
t : Fin (s i).1 ↪o J, the realization of (s i).2 on b ∘ t matches
h.template.truth (s i).2.
The sequence b is defined as the interpretation of the J-indexed constant
symbol under the L[[J]]-structure. The L-structure used for .Realize is
the reduct along lhomWithConstants L J, introduced via letI inside the
existential body.
EM realization from a bare compactness hypothesis.
EM stretching along an arbitrary target order (bare compactness oracle).
Same content as stretch_restricted_of_fullFragment, but driven by a bare
compactness hypothesis on L[[J]] instead of a FullBarwiseFragment.
EM stretching along an arbitrary target order — sequence form (bare compactness oracle).
Compact-oracle variant of stretch_restricted_sequence_of_fullFragment.
Morley–Hanf-oriented corollaries #
Sentence preservation under EM stretching.
If the formula family s enumerates a sentence φ : L.BoundedFormulaω Empty 0
(i.e., ⟨0, φ⟩ ∈ Set.range s), then the stretched model N realizes φ
iff the source model M does.
This is the form Morley–Hanf needs: any sentence M satisfies survives to
the stretched model.
The 2-ary Lω₁ω disequality formula x₀ ≠ x₁.
Equations
Instances For
The Morley seed of a sentence φ: the concrete two-formula family the Morley–Hanf tail
bridge feeds the EM machinery — φ itself, the disequality x₀ ≠ x₁, and repeated φ-filler.
The honest tail-template residual quantifies over exactly this seed
(MorleySeedTailTemplateRealizable in Conditional/MorleyHanfTransfer.lean), NOT over arbitrary
formula sequences: an arbitrary sequence can enumerate {Pᵢ x}ᵢ ∪ {⋀ᵢ Pᵢ x} against a "height"
model, whose tail template is finitely satisfiable but unsatisfiable — a genuine L_{ω₁ω}
compactness failure.
Equations
Instances For
The Morley seed needs no extraction: ANY pairwise-distinct sequence is fully
Lω₁ω-indiscernible on Set.range (morleySeed φ) — the arity-0 members ignore their tuples,
and the disequality is true on every strictly monotone pair of a pairwise-distinct sequence.
This is why the definitive Morley–Hanf route consumes no Ramsey/Erdős–Rado extraction at all:
Infinite.natEmbedding already supplies a seed-indiscernible sequence.
Injectivity of the stretched sequence.
If the source sequence a : I → M is pairwise distinct on its index set and
the formula family s enumerates the 2-ary disequality formula
(disEqFormula : L.BoundedFormulaω Empty 2), then the stretched sequence
b : J → N is injective. Hence #N ≥ #J: cardinality is amplified from
I to J.
Restricted-indiscernibility variants #
These _on theorems take IsLomega1omegaIndiscernibleOn a (Set.range s)
instead of the full IsLomega1omegaIndiscernible a, and state their
conclusions against (templateOfSeq a).truth rather than h.template.truth.
Tranche 2b of the Phase 2 refactor.
Compact-oracle adapter under restricted indiscernibility.
EM stretching (sentence form, fullFragment, restricted source).
EM stretching (sentence form, compact oracle, restricted source).
EM stretching (sequence form, fullFragment, restricted source).
EM stretching (sequence form, compact oracle, restricted source).