experiment: freeze KP teaching-signal ablation

1 files changed, 10 insertions, 4 deletions

diff --git a/sdil/conv.py b/sdil/conv.py
index ebb29ab..1034202 100644
--- a/sdil/conv.py
+++ b/sdil/conv.py
@@ -820,7 +820,16 @@ class CIFARKPMixedTrafficResNet(CIFARKPResNet):
     def mixed_apical_components(self, instruction, hiddens, rule,
                                 compute_matched=False,
                                 neutral_projection=False):
-        """Return used, raw, innovation, matched, and traffic fields."""
+        """Return used, raw, innovation, matched, and traffic fields.
+
+        When ``neutral_projection`` is enabled, every rule pays for and
+        reports the same instruction-off projection.  Only the innovation
+        rule applies the subtractive direction.  Raw keeps the unmodified
+        apical vector, while matched keeps its direction and borrows only the
+        projected innovation norm.  This makes raw and matched strict sham
+        controls for the subtractive operation without changing their local
+        information or observation budget.
+        """
         if rule not in ("raw", "matched", "innovation"):
             raise ValueError(f"unknown mixed-traffic rule: {rule}")
         if not (len(instruction) == len(hiddens) == self.n_hidden):
@@ -829,9 +838,6 @@ class CIFARKPMixedTrafficResNet(CIFARKPResNet):
         projected_neutral = None
         projection_report = None
         if neutral_projection:
-            if rule != "innovation":
-                raise ValueError(
-                    "neutral projection is defined only for innovation")
             projected_neutral, projection_report = (
                 self.neutral_residual_projection(hiddens))
         raw = []