Module double_ssd 

Double-SSD pathway (VikramLex-style)

Realises the Mamba-3 trapezoidal recurrence as two standard SSD calls that reuse the Mamba-2-like kernels:

• γ-SSM: hᵞₜ = αₜ hᵞₜ₋₁ + γₜ Bₜ xₜ (current token)
• β-SSM: hᵝₜ = αₜ hᵝₜ₋₁ + βₜ Bₜ₋₁ xₜ₋₁ (previous token)
• hₜ = hᵞₜ + hᵝₜ.

Simple and easy to verify, at the cost of ~2× the intra-chunk and chunk-state memory of the single_ssd pathway.

Modules

cache

The double-SSD cache (ssm/k_state/v_state/cum_angle; no conv cache).

double_ssd

forward_double_ssd / step_double_ssd and the RoPE helpers.

prelude

Public re-exports for the double-SSD pathway.

ssd

The standard SSD kernels reused by both the γ and β passes. Standard MIMO-first SSD kernels reused by the double-SSD γ and β passes.