Lemma 14.4, Case I: unconditional same-constant successor #
This is the final assembly against the source interfaces. The recurrence and
IH are the actual finite ones; Σ₀ is first identified with the single source
endpoint, Σ₁₁ is the internal Lemma-8.7 estimate, Σ₁₂ uses the natural
ceiling, and Σ₂ vanishes in the genuine κ = 1 Case-I range.
The only upstream name intentionally isolated by this file is
caseI1423_sigmaZero_realEndpoint_sourceBound. It is the expected real
endpoint source estimate for the explicit Claim-14.5 remainder, not a bound
on Σ₀, a mainSum estimate, or an absorption hypothesis. Once that producer
is present, the theorem below has no Sigma-bound, mainSum, or absorption
premise.
Eventual Case-I successor with literally the same constant C in the
induction hypothesis, inherited budget, and conclusion.