Establishes the H^k complexity ladder as a projective hierarchy: H0 (classical/tropical) and H1 (Clifford/stabiliser) are projective shadows of H2 (magic/metaplectic). The Meld — the H2 completion of the ISA — projects onto Origami (H0+H1 shadow) and Forge (H1 shadow) in the same way that a 3D object projects onto 2D shadows. Derives the Palmer Invariant Space-time conjecture as the fixed-point condition of Penrose objective reduction within this framework.
Establishes the H^k complexity ladder as a projective hierarchy: H0 (classical/tropical) and H1 (Clifford/stabiliser) are projective shadows of H2 (magic/metaplectic). The Meld — the H2 completion of the ISA — projects onto Origami (H0+H1 shadow) and Forge (H1 shadow) in the same way that a 3D object projects onto 2D shadows. Derives the Palmer Invariant Space-time conjecture as the fixed-point condition of Penrose objective reduction within this framework.
PENDING QUALITY AUDIT (2026-08). The file is restricted while this record is reviewed as part of a systematic audit of the author's corpus. It has not yet been assessed. Metadata and DOI remain public, and access can be requested. We complete the TRS trilogy — Origami (β→∞, tropical, classical), Forge (0<β<∞, real, statistical), Meld (β=it, complex, quantum) — by showing that the Meld ISA is the quantum circuit model expressed in the TRS semiring language. Three results follow. Result 1 (ISA completeness). The Clifford group equals the Meld ISA without the BIND opcode. Universal quantum computation equals Meld plus BIND. The T-gate T=diag(1,,eiπ/4) is the BIND opcode at j=21 — the Fano associator obstruction of Paper 407, applied to qubit representations. The magic-typing classification of Papers 365/366 maps exactly onto the 731-ISA opcode hierarchy: Clifford gates occupy Fano-line orbits (SPLIT/FLIP/TWIST at Clifford angles); the T-gate occupies the non-collinear Fano triple (BIND). Result 2 (Quantum algorithm factory). Every classical algorithm of the form argmaxg∈Gf(g) over an abelian group G has a C-MGE quantum counterpart C-MGE(f)=SPLITG⋅FLIP(f)⋅SPLAT, giving exponential speedup via quantum Fourier sampling whenever G is abelian and f has a hidden subgroup concentrating Fourier mass. Shor's algorithm decomposes into three ISA layers: Layer 1 (Origami — classical modular exponentiation), Layer 2 (Meld — QFT as SPLIT-TWIST-FLIP cascade), Layer 3 (Origami — measurement as tropical projection). "Frozen-Shor" (Origami ISA, β→∞) recovers classical exhaustive search at cost O(N). "Warm-Shor" (Forge ISA, real β) gives Grover-like O(N) thermal concentration. Full Shor (Meld, β=it) achieves O(logN) via destructive interference — a resource unavailable in either real ISA. New algorithm candidates follow by identifying the symmetry group of the target problem: equivariant ML, quantum persistent homology (Lloyd-Garnerone-Zanardi 2016), and Boson Sampling (Aaronson-Arkhipov 2011) all fit the five-step factory template. Result 3 (ML-KEM structural no-go). ML-KEM (Module-LWE) is immune because LWE noise exponentially suppresses every Fourier component: Ee∼Dσ[ei⟨ξ,e⟩]=e−∣ξ∣2σ2/2. No Fourier peak exists; SPLAT cannot extract a period. The deeper reason is that worst-case LWE reduces to the dihedral hidden subgroup problem (Regev 2002) — a non-abelian problem for which no efficient Meld program is known. Breaking ML-KEM would require a BIND opcode capable of distinguishing dihedral cosets, a capability not established for the current 731-Meld. The Hk complexity ladder (Paper 420) is realised by the trilogy: H0 (tree) = Origami, H1 (loop) = Forge/BPP, H2 (surface) = Meld/BQP. The T-gate is the H2 generator that lifts computation off the stabiliser submanifold into the curved interior of the Fisher information metric. Series: Paper 258 (Origami ISA) → Paper 419 (Forge ISA) → Paper 443 (⊕β semiring, six pairs) → Paper 453 (multi-sector Forge) → Paper 454 (this paper — Meld ISA, trilogy complete). Related identifiers (Cites) Paper 258 Origami ISA: doi:10.5281/zenodo.19916429 Paper 419 Forge ISA: doi:10.5281/zenodo.20694527 Paper 443 ⊕_β semiring: doi:10.5281/zenodo.20752384 Paper 407 Associamancy: doi:10.5281/zenodo.20702223 Paper 365 Fano Magic Factory: doi:10.5281/zenodo.20541583 Paper 366 CS Magic Composition: doi:10.5281/zenodo.20541665 Paper 445 Kitaev anyons: doi:10.5281/zenodo.20752352 Paper 453 Multi-sector Forge: doi:10.5281/zenodo.20773423 Paper 420 H^k complexity ladder: doi:10.5281/zenodo.20773526
A fundamental problem in fault-tolerant quantum computation is the tradeoff between universality and dimensionality, exemplified by the the Bravyi-König bound for n-dimensional topological stabilizer codes. In this work, we extend topological Pauli stabilizer codes to a broad class of n-dimensional Clifford hierarchy stabilizer codes. These codes correspond to the (n+1)D Dijkgraaf-Witten gauge theories with non-Abelian topological order. We construct transversal non-Clifford gates through automorphism symmetries represented by cup products. In 2D, we obtain the first transversal non-Clifford logical gates including T and CS for Clifford stabilizer codes, using the automorphism of the twisted Z23 gauge theory (equivalent to D4 topological order). We also combine it with the just-in-time decoder to fault-tolerantly prepare the logical T magic state in O(d) rounds via code switching. In 3D, we construct a transversal logical T gate in a non-Clifford stabilizer code at the third level of the Clifford hierarchy, located on a tetrahedron corresponding to a twisted Z24 gauge theory. Our constructions surpass the Bravyi-König bound by achieving the logical gates in the (n+1)-th level of Clifford hierarchy in n spatial dimension.
The Maslov-Gibbs Einsum (MGE) is not a single algorithm but a family of tensor contraction schemes indexed by the cohomological level Hk of the physical system. This paper identifies three distinct forms: H0 MGE (classical/tropical): contraction over the min-plus tropical semiring, corresponding to Maslov dequantisation (ℏ→0). Finds the dominant classical path; computational class P. H1 MGE (Clifford/stabiliser): contraction over the stabiliser calculus of the Clifford group C2. Captures quantum interference within the stabiliser sector. Classically simulable in polynomial time by the Gottesman-Knill theorem, but exponentially more expressive than H0: captures non-local correlations, entanglement, and quantum error correction. H2 MGE (metaplectic/magic): contraction with Maslov index phase corrections. Each gate composition g∘h acquires a Z2 phase factor (−1)τ(L,gL,ghL) from the Maslov index of three Lagrangian subspaces. The TWIST opcode in the Origami ISA counts how many times this correction fires; TWIST >0 is necessary and sufficient for H2 MGE. Computational class BQP-hard. The central observation is that Viktor Maslov named both ends of this ladder: Maslov dequantisation (H0, 1990s) and the Maslov index (H2, 1965) are not coincidentally related — they are the two limits of the same quantisation programme, with the Clifford/Berry-phase level H1 interpolating between them. The name "Maslov-Gibbs Einsum" was more prophetic than intended: Maslov's index governs the H2 correction as well as the H0 tropical limit. The Origami ISA compiler selects the MGE form automatically: TWIST =0 implies H1 MGE suffices; TWIST >0 requires H2 MGE. This makes the Schur multiplier Z2 a compile-time certificate for quantum advantage. The paper also introduces the Penrose empire problem as a non-quantum illustration of why H0 local consistency checking cannot detect H1 and H2 obstructions, and discusses the H3 frontier (Dijkgraaf-Witten state sums, Fibonacci anyon braiding) as the next level beyond current qubit hardware. Keywords Maslov-Gibbs Einsum, tropical semiring, Maslov dequantisation, Maslov index, Clifford group, stabiliser calculus, metaplectic group, cohomological filtration, Hk tower, TWIST opcode, Origami ISA, Gottesman-Knill theorem, quantum advantage, BQP, magic states, tensor contraction, Penrose tiling, Dijkgraaf-Witten, topological quantum computation
The Clifford hierarchy C1⊂C2⊂⋯ was introduced by Gottesman and Chuang (arXiv:quant-ph/9908010) to characterize gates that admit fault-tolerant implementation by gate teleportation. Yet, despite its rich mathematical structure and the attention it has received in recent years, little is known about Ck for k>3. Most progress has focused on identifying structural properties of restrictions of the hierarchy, such as diagonal gates and gates on systems of small dimension d or with few qudits.
The generalized semi-Clifford conjecture, proposed by Zeng et al. (arXiv:0712.2084), states that every gate in ∪kCk is, up to multiplication by Cliffords, the product of a permutation and a diagonal matrix. Beigi and Shor proved the case d=2, k=3 (arXiv:0810.5108) and Pllaha et al. found an alternative proof by exploiting fixed points of the conjugation map induced by (a Clifford correction of) U∈C3 on the span of maximal stabilizer subgroups (arXiv:2006.14040). By extending their fixed-point arguments to the group Γ1(U) generated by UPU† and beyond, we prove the conjecture for k≤4 and any prime dimension d.
Our proof centers on conjugation groups Γ1(U),Γ2(U),… of U∈Ck, which we expect to be a useful tool in the study of the Clifford hierarchy more generally. We also show a natural sufficient condition on such groups for gates in higher levels to be generalized semi-Clifford.