core/algebra/holonomy.py

93 lines
3.3 KiB
Python

"""
Holonomy prompt encoding.
A prompt w1, w2, ..., wn is encoded as the geometric holonomy of its
forward+reverse versor walk. The walk closes, producing a bounded algebraic
summary of the prompt path.
The input word objects must already be valid construction-time versors.
Holonomy may unitize intermediate construction products to prevent float32
scale blow-up, but never repairs propagation state.
"""
from __future__ import annotations
import numpy as np
from .cl41 import geometric_product, reverse as cl_reverse
from .versor import unitize_versor
from .cga import cga_inner
def _renorm_if_needed(H: np.ndarray, step: int, renorm_every: int) -> np.ndarray:
"""Bound accumulator scale to prevent float32 overflow on long prompts."""
if renorm_every <= 0 or step % renorm_every != 0:
return H
norm = float(np.linalg.norm(H))
if not np.isfinite(norm) or norm < 1e-12:
raise ValueError("holonomy accumulator became null/non-finite during encoding.")
return (H / norm).astype(H.dtype)
def _position_rotor(step: int, dtype: np.dtype) -> np.ndarray:
negative_bivectors = (6, 7, 9, 10, 12, 14)
rotor = np.zeros(32, dtype=dtype)
theta = (step + 1) * 0.17320508075688773
rotor[0] = np.cos(theta)
rotor[negative_bivectors[step % len(negative_bivectors)]] = np.sin(theta)
return rotor
def holonomy_encode(
word_versors: list,
alpha: float = 0.5,
weights: list | None = None,
renorm_every: int = 8,
) -> np.ndarray:
"""
Compute the holonomy of the word versor sequence.
Forward walk: F = w1 * w2 * ... * wn (weighted by word frequency inverse)
Reverse walk: R = (1-alpha) * reverse(wn) * ... * reverse(w1)
Holonomy: H = F * R
Construction-time unitization is used at the boundary and at the final
product. A bounded Euclidean renormalization is also applied every
`renorm_every` steps to prevent long prompt overflow in float32.
"""
if not word_versors:
raise ValueError("Cannot encode empty prompt.")
if not 0.0 <= alpha <= 1.0:
raise ValueError("alpha must be in [0, 1].")
n = len(word_versors)
if weights is None:
weights = [1.0] * n
if len(weights) != n:
raise ValueError("weights length must match word_versors length.")
dtype = np.result_type(*word_versors)
if dtype not in (np.dtype(np.float32), np.dtype(np.float64)):
dtype = np.dtype(np.float32)
# Forward accumulation. Each token is carried through a deterministic
# position rotor so path order survives even for scalar/vector fixtures.
p0 = _position_rotor(0, dtype)
w0 = unitize_versor(np.asarray(word_versors[0], dtype=dtype) * weights[0])
F = unitize_versor(geometric_product(geometric_product(p0, w0), cl_reverse(p0)))
for k in range(1, n):
p = _position_rotor(k, dtype)
w = unitize_versor(np.asarray(word_versors[k], dtype=dtype) * weights[k])
step = unitize_versor(geometric_product(geometric_product(p, w), cl_reverse(p)))
F = geometric_product(F, step)
F = _renorm_if_needed(F, k, renorm_every)
return unitize_versor(F)
def holonomy_similarity(H1: np.ndarray, H2: np.ndarray) -> float:
"""
Compare two holonomies via CGA inner product.
Used for prompt-level semantic similarity without embedding lookup.
"""
return cga_inner(unitize_versor(H1), unitize_versor(H2))