Little-endian binary successor — proof internals #
This file proves the pure ripple semantics and the exact full-frame execution
of TM.binarySuccTM. The carry proof uses a private head-independent binary
content predicate, generalized over the already-zeroed low-order prefix.
Exact rewind and carry runs #
Public-theorem internals #
theorem
Complexity.TM.binarySuccTM_reachesIn_frame_internal
{n : ℕ}
(idx : Fin n)
(value : ℕ)
(inp₀ : Tape)
(work₀ : Fin n → Tape)
(out₀ : Tape)
(hvalue : (work₀ idx).HasBinaryNat value)
(hinp : inp₀.read ≠ Γ.start)
(hother : ∀ (i : Fin n), i ≠ idx → (work₀ i).read ≠ Γ.start)
(hout : out₀.read ≠ Γ.start)
:
∃ (c' : Cfg n (binarySuccTM idx).Q),
(binarySuccTM idx).reachesIn (binarySuccTime value)
{ state := (binarySuccTM idx).qstart, input := inp₀, work := work₀, output := out₀ } c' ∧ (binarySuccTM idx).halted c' ∧ c'.input = inp₀ ∧ (∀ (i : Fin n), i ≠ idx → c'.work i = work₀ i) ∧ (c'.work idx).HasBinaryNat (value + 1) ∧ c'.output = out₀
theorem
Complexity.TM.binarySuccTM_hoareTime_frame_internal
{n : ℕ}
(idx : Fin n)
(value : ℕ)
(inp₀ : Tape)
(work₀ : Fin n → Tape)
(out₀ : Tape)
(hvalue : (work₀ idx).HasBinaryNat value)
(hinp : inp₀.read ≠ Γ.start)
(hother : ∀ (i : Fin n), i ≠ idx → (work₀ i).read ≠ Γ.start)
(hout : out₀.read ≠ Γ.start)
:
(binarySuccTM idx).HoareTime
(fun (inp : Tape) (work : Fin n → Tape) (out : Tape) => inp = inp₀ ∧ work = work₀ ∧ out = out₀)
(fun (inp : Tape) (work : Fin n → Tape) (out : Tape) =>
inp = inp₀ ∧ (∀ (i : Fin n), i ≠ idx → work i = work₀ i) ∧ (work idx).HasBinaryNat (value + 1) ∧ out = out₀)
(binarySuccTime value)
theorem
Complexity.TM.binarySuccTM_hoareTimeSpace_frame_internal
{n : ℕ}
(idx : Fin n)
(value inputLength initialSpace : ℕ)
(inp₀ : Tape)
(work₀ : Fin n → Tape)
(out₀ : Tape)
(hvalue : (work₀ idx).HasBinaryNat value)
(hinp : inp₀.read ≠ Γ.start)
(hother : ∀ (i : Fin n), i ≠ idx → (work₀ i).read ≠ Γ.start)
(hout : out₀.read ≠ Γ.start)
(hinitial :
{ state := (binarySuccTM idx).qstart, input := inp₀, work := work₀, output := out₀ }.WithinAuxSpace inputLength
initialSpace)
:
(binarySuccTM idx).HoareTimeSpace
(fun (inp : Tape) (work : Fin n → Tape) (out : Tape) => inp = inp₀ ∧ work = work₀ ∧ out = out₀)
(fun (inp : Tape) (work : Fin n → Tape) (out : Tape) =>
inp = inp₀ ∧ (∀ (i : Fin n), i ≠ idx → work i = work₀ i) ∧ (work idx).HasBinaryNat (value + 1) ∧ out = out₀)
(binarySuccTime value) inputLength (initialSpace + binarySuccTime value)
theorem
Complexity.TM.binarySuccTM_isTransducer_internal
{n : ℕ}
(idx : Fin n)
:
(binarySuccTM idx).IsTransducer