Update legacy C1-C3/RC1-RC4 references to unified U1-U4 grammar

Co-authored-by: fermga <203334638+fermga@users.noreply.github.com>

Author: Copilot

src/tnfr/operators/algebra.py

@@ -92,8 +92,10 @@ def validate_identity_property(
 
     Notes
     -----
-    Due to TNFR grammar constraints (C1: must end with terminator,
-    C2: must include stabilizer), we test identity by comparing:
+    Due to TNFR grammar constraints (U1b: must end with closure,
+    U2: must include stabilizer), we test identity by comparing:
+    
+    [Legacy note: Previously referenced C1-C2. See docs/grammar/DEPRECATION-INDEX.md]
 
     - Path 1: operator → Coherence → Dissonance (OZ terminator)
     - Path 2: operator → Coherence → Silence (SHA terminator)

src/tnfr/operators/preconditions/__init__.py

@@ -286,7 +286,7 @@ def validate_coupling(G: "TNFRGraph", node: "NodeId") -> None:
         Minimum EPI magnitude required for coupling
     UM_MIN_VF : float, default 0.01
         Minimum structural frequency required for coupling
-    UM_STRICT_PHASE_CHECK : bool, default True (changed from False per RC3)
+    UM_STRICT_PHASE_CHECK : bool, default True (changed from False per U3)
         Enable strict phase compatibility checking with existing neighbors.
         **MANDATORY per AGENTS.md Invariant #5**: "no coupling is valid without
         explicit phase verification (synchrony)"
@@ -312,7 +312,9 @@ def validate_coupling(G: "TNFRGraph", node: "NodeId") -> None:
     Notes
     -----
     **IMPORTANT**: Phase compatibility check is now MANDATORY by default
-    (UM_STRICT_PHASE_CHECK=True) to align with AGENTS.md Invariant #5 and RC3.
+    (UM_STRICT_PHASE_CHECK=True) to align with AGENTS.md Invariant #5 and U3.
+    
+    [Legacy note: Previously referenced RC3. See docs/grammar/DEPRECATION-INDEX.md]
 
     Set UM_STRICT_PHASE_CHECK=False to disable (NOT RECOMMENDED - violates
     canonical physics requirements).
@@ -334,7 +336,9 @@ def validate_coupling(G: "TNFRGraph", node: "NodeId") -> None:
     --------
     Coupling : UM operator that uses this validation
     AGENTS.md : Invariant #5 (phase check mandatory)
-    EMERGENT_GRAMMAR_ANALYSIS.md : RC3 derivation
+    UNIFIED_GRAMMAR_RULES.md : U3 derivation
+    
+    [Legacy: Previously referenced EMERGENT_GRAMMAR_ANALYSIS.md RC3]
     """
     import math
 
@@ -361,7 +365,7 @@ def validate_coupling(G: "TNFRGraph", node: "NodeId") -> None:
             "Coupling", f"Structural frequency too low (νf={vf:.3f} < {min_vf:.3f})"
         )
 
-    # RC3: Phase compatibility check
+    # U3: Phase compatibility check (was RC3)
     # Per AGENTS.md Invariant #5: "no coupling is valid without explicit phase verification"
     # Changed from False to True to align with canonical physics requirements
     strict_phase = bool(G.graph.get("UM_STRICT_PHASE_CHECK", True))

src/tnfr/validation/rules.py

@@ -230,15 +230,18 @@ def _check_compatibility(ctx: "GrammarContext", n, cand: Glyph | str) -> Glyph |
     """Verify canonical transition compatibility based on TNFR structural dynamics.
 
     Note: Frequency-based validation (R5) has been removed as it was not a
-    fundamental physical constraint. Only C1-C3 constraints remain:
-    - C1: EXISTENCE & CLOSURE (valid start/end)
-    - C2: BOUNDEDNESS (stabilizers required)
-    - C3: THRESHOLD PHYSICS (bifurcations need context)
+    fundamental physical constraint. Only U1-U4 constraints remain:
+    - U1: STRUCTURAL INITIATION & CLOSURE (valid start/end)
+    - U2: CONVERGENCE & BOUNDEDNESS (stabilizers required)
+    - U3: RESONANT COUPLING (phase compatibility)
+    - U4: BIFURCATION DYNAMICS (bifurcations need context)
+    
+    [Legacy note: Previously referenced C1-C3. See docs/grammar/DEPRECATION-INDEX.md]
 
     These are validated in grammar.py, not here. This function now simply
     allows all transitions - validation happens at sequence level.
     """
-    # All transitions allowed - validation at sequence level via C1-C3
+    # All transitions allowed - validation at sequence level via U1-U4
     return cand
 
 

tests/unit/operators/test_sha_algebra.py

@@ -32,7 +32,8 @@
 - Identity property with Emission and complex sequences
 - Idempotence through consistent SHA behavior across contexts
 - Commutativity with Contraction operator
-- All tests respect TNFR grammar constraints (C1, C2, C3)
+- All tests respect TNFR grammar constraints (U1-U4)
+  Note: Legacy reference to C1-C3 constraints - see docs/grammar/DEPRECATION-INDEX.md
 """
 
 from __future__ import annotations