sinsemilla::merkle.rs: Rename advice column names for clarity.

src/circuit/gadget/sinsemilla/merkle.rs

@@ -62,10 +62,10 @@ pub struct MerkleConfig<
     const K: usize,
     const MAX_WORDS: usize,
 > {
-    a: Column<Advice>,
-    b: Column<Advice>,
-    c: Column<Advice>,
-    left: Column<Advice>,
+    a_a0: Column<Advice>,
+    b_a1: Column<Advice>,
+    c_b0: Column<Advice>,
+    left_b1: Column<Advice>,
     right: Column<Advice>,
     l_star_plus1: Column<Fixed>,
     perm: Permutation,
@@ -111,10 +111,10 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
             sinsemilla_config.perm.clone(),
         );
 
-        let a = advices[0];
-        let b = advices[1];
-        let c = advices[2];
-        let left = advices[3];
+        let a_a0 = advices[0];
+        let b_a1 = advices[1];
+        let c_b0 = advices[2];
+        let left_b1 = advices[3];
         let right = advices[4];
 
         let l_star_plus1 = meta.fixed_column();
@@ -126,16 +126,16 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
         // `b = b_0||b_1` = (bits 240..=254 of `left`) || (bits 0..=234 of `right`)
         // `c = bits 235..=254 of `right`
         meta.create_gate("Merkle path validity check", |meta| {
-            let a_whole = meta.query_advice(a, Rotation::cur());
-            let b_whole = meta.query_advice(b, Rotation::cur());
-            let c_whole = meta.query_advice(c, Rotation::cur());
-            let left_node = meta.query_advice(left, Rotation::cur());
+            let a_whole = meta.query_advice(a_a0, Rotation::cur());
+            let b_whole = meta.query_advice(b_a1, Rotation::cur());
+            let c_whole = meta.query_advice(c_b0, Rotation::cur());
+            let left_node = meta.query_advice(left_b1, Rotation::cur());
             let right_node = meta.query_advice(right, Rotation::cur());
 
-            let a_0 = meta.query_advice(a, Rotation::next());
-            let a_1 = meta.query_advice(b, Rotation::next());
-            let b_0 = meta.query_advice(c, Rotation::next());
-            let b_1 = meta.query_advice(left, Rotation::next());
+            let a_0 = meta.query_advice(a_a0, Rotation::next());
+            let a_1 = meta.query_advice(b_a1, Rotation::next());
+            let b_0 = meta.query_advice(c_b0, Rotation::next());
+            let b_1 = meta.query_advice(left_b1, Rotation::next());
 
             let l_star_plus1 = meta.query_fixed(l_star_plus1, Rotation::cur());
 
@@ -165,10 +165,10 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
         });
 
         MerkleConfig {
-            a,
-            b,
-            c,
-            left,
+            a_a0,
+            b_a1,
+            c_b0,
+            left_b1,
             right,
             l_star_plus1,
             perm: sinsemilla_config.perm.clone(),
@@ -329,7 +329,7 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
                     copy(
                         &mut region,
                         || "copy a",
-                        config.a,
+                        config.a_a0,
                         0,
                         &(a.into()),
                         &config.perm,
@@ -338,7 +338,7 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
                     copy(
                         &mut region,
                         || "copy b",
-                        config.b,
+                        config.b_a1,
                         0,
                         &b.into(),
                         &config.perm,
@@ -347,13 +347,20 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
                     copy(
                         &mut region,
                         || "copy c",
-                        config.c,
+                        config.c_b0,
                         0,
                         &c.into(),
                         &config.perm,
                     )?;
                     // Copy and assign the left node at the correct position.
-                    copy(&mut region, || "left", config.left, 0, &left, &config.perm)?;
+                    copy(
+                        &mut region,
+                        || "left",
+                        config.left_b1,
+                        0,
+                        &left,
+                        &config.perm,
+                    )?;
                     // Copy and assign the right node at the correct position.
                     copy(
                         &mut region,
@@ -367,28 +374,28 @@ impl<C: CurveAffine, const PATH_LENGTH: usize, const K: usize, const MAX_WORDS:
                     // Witness the piece `a_0`.
                     region.assign_advice(
                         || "a_0",
-                        config.a,
+                        config.a_a0,
                         1,
                         || a_0.ok_or(Error::SynthesisError),
                     )?;
                     // Witness the piece `a_1`.
                     region.assign_advice(
                         || "a_1",
-                        config.b,
+                        config.b_a1,
                         1,
                         || a_1.ok_or(Error::SynthesisError),
                     )?;
                     // Witness the piece `b_0`.
                     region.assign_advice(
                         || "b_0",
-                        config.c,
+                        config.c_b0,
                         1,
                         || b_0.ok_or(Error::SynthesisError),
                     )?;
                     // Witness the piece `b_1`.
                     region.assign_advice(
                         || "b_1",
-                        config.left,
+                        config.left_b1,
                         1,
                         || b_1.ok_or(Error::SynthesisError),
                     )?;