diff --git a/crates/ogar-loco/src/lib.rs b/crates/ogar-loco/src/lib.rs
index 69d66d2a..41dc1322 100644
--- a/crates/ogar-loco/src/lib.rs
+++ b/crates/ogar-loco/src/lib.rs
@@ -588,6 +588,41 @@ impl FnIndex {
     /// Read a call argument. `procedures_defreturn` argument access.
     pub const PROC_ARG: FnIndex = FnIndex(0x85);
 
+    // ── epistemic mask algebra (0x86..0x8B, minted 2026-09-01) ──────────
+    //
+    // The operator's essence-directive, verbatim in intent: primitives like
+    // Belnap become reusable bytecode macros here, for literally everything.
+    // Semantics are owned by `lance-graph-contract::epistemic_bassin` (the
+    // scalar oracles these calls are parity-tested against); batch SIMD
+    // execution is ndarray's shipped W1a-#9 `ternlog` (native VPTERNLOGQ).
+    // Green-certified atoms only — Hambly-Lyons is deliberately ABSENT
+    // while jc Pillar 11 is red (the red-pillar mint rule).
+
+    /// Any 3-input boolean over stacked masks: pops three masks, and the
+    /// call's ONE VALUE BYTE **is the 8-bit truth table** (IMM bit index =
+    /// `(a << 2) | (b << 1) | c`) — one FnIndex covers all 256 stacked-mask
+    /// combinators, which is the purest `(function : value)` in the ABI.
+    /// Canonical tables (asked-contested 0x80, asked-silent 0x02 = the
+    /// missing link, …) live in `epistemic_bassin::sweep_ternlog`.
+    pub const TERNLOG: FnIndex = FnIndex(0x86);
+    /// Belnap/FDE knowledge-order join of two mask PAIRS — bitwise OR per
+    /// side; provably the state layer of one-hop accumulation.
+    pub const BELNAP_JOIN: FnIndex = FnIndex(0x87);
+    /// Shannon expected-information-gain readout: pops (before, after)
+    /// candidate counts, pushes whole bits of narrowing (u4-saturated).
+    /// Proprioception, never evidence.
+    pub const INFO_GAIN: FnIndex = FnIndex(0x88);
+    /// EWA tension readout: pops (log-norm growth, certificate bound),
+    /// pushes quarters-of-the-bound (u4; 7 = the 1.75× PASS slack).
+    pub const SIGMA_TENSION: FnIndex = FnIndex(0x89);
+    /// One-hop accumulation of a LIST of bassin pairs into the parent pair —
+    /// exact sums per side, one clamp; a parent expresses its DIRECT
+    /// children only.
+    pub const ACCUMULATE: FnIndex = FnIndex(0x8A);
+    /// One-hop contested-ness: pops (list of pairs, axis), pushes the
+    /// four-state Shannon entropy of the children's stances on that axis.
+    pub const STANCE_ENTROPY: FnIndex = FnIndex(0x8B);
+
     /// Is this a **shared computational** operation — one that means the same
     /// thing in every vocabulary?
     ///
diff --git a/crates/ogar-loco/src/vocabulary.rs b/crates/ogar-loco/src/vocabulary.rs
index 68dc24b1..15c30485 100644
--- a/crates/ogar-loco/src/vocabulary.rs
+++ b/crates/ogar-loco/src/vocabulary.rs
@@ -89,6 +89,17 @@ pub mod shared_core {
             | FnIndex::FOR_EACH => 1,
             // from, to, by — then a body.
             FnIndex::FOR_RANGE => 3,
+            // ── epistemic mask algebra (0x86..0x8B). TERNLOG pops three
+            // masks; its truth table rides as the call's value byte, never
+            // as an operand. The two list-consuming ops take the LIST as
+            // one operand (the arity of the call, not of the children —
+            // which is how the variadic-refusal rule stays satisfied).
+            FnIndex::TERNLOG => 3,
+            FnIndex::BELNAP_JOIN
+            | FnIndex::INFO_GAIN
+            | FnIndex::SIGMA_TENSION
+            | FnIndex::STANCE_ENTROPY => 2,
+            FnIndex::ACCUMULATE => 1,
             // Leave the enclosing loop / iteration. No operand, no body.
             FnIndex::BREAK | FnIndex::CONTINUE => 0,
             // ── leaves — they push, they do not consume.
@@ -337,6 +348,12 @@ pub mod shared_core {
             FnIndex::ACOS => "ACOS",
             FnIndex::ATAN => "ATAN",
             FnIndex::ATAN2 => "ATAN2",
+            FnIndex::TERNLOG => "TERNLOG",
+            FnIndex::BELNAP_JOIN => "BELNAP_JOIN",
+            FnIndex::INFO_GAIN => "INFO_GAIN",
+            FnIndex::SIGMA_TENSION => "SIGMA_TENSION",
+            FnIndex::ACCUMULATE => "ACCUMULATE",
+            FnIndex::STANCE_ENTROPY => "STANCE_ENTROPY",
             FnIndex::RANDOM_INT => "RANDOM_INT",
             FnIndex::RANDOM_FLOAT => "RANDOM_FLOAT",
             FnIndex::CONSTRAIN => "CONSTRAIN",
@@ -1417,8 +1434,11 @@ mod coverage {
             );
         }
 
-        // And the census itself, pinned: 95 named operations (96 constants
-        // minus NOP, which is not an operation), 5 refused, 90 covered.
-        assert_eq!(named, 95, "the named census moved — re-pin deliberately");
+        // And the census itself, pinned: 101 named operations (102 constants
+        // minus NOP, which is not an operation), 5 refused, 96 covered.
+        // Re-pinned 2026-09-01: +6 for the epistemic mask-algebra band
+        // (0x86..0x8B — TERNLOG, BELNAP_JOIN, INFO_GAIN, SIGMA_TENSION,
+        // ACCUMULATE, STANCE_ENTROPY), minted into the reserved core slots.
+        assert_eq!(named, 101, "the named census moved — re-pin deliberately");
     }
 }