Simplify the pubscalars_or test

tests/pubscalars_or.rs

@@ -7,11 +7,9 @@ use sigma_compiler::*;
 
 fn pubscalars_or_test_val(b_val: u128) -> Result<(), sigma_rs::errors::Error> {
     sigma_compiler! { proof,
-        (x, z, rand r, rand s, pub a, pub b),
-        (C, D, const cind A, const cind B),
+        (x, rand r, pub a, pub b),
+        (C, const cind A, const cind B),
         C = x*A + r*B,
-        D = z*A + s*B,
-        z = 2*x + a,
         OR (
             b = 2*a,
             b = 2*a - 3,
@@ -23,16 +21,13 @@ fn pubscalars_or_test_val(b_val: u128) -> Result<(), sigma_rs::errors::Error> {
     let A = G::hash_from_bytes::<Sha512>(b"Generator A");
     let B = G::generator();
     let r = Scalar::random(&mut rng);
-    let s = Scalar::random(&mut rng);
     let x = Scalar::from_u128(5);
-    let z = Scalar::from_u128(17);
     let a = Scalar::from_u128(7);
     let b = Scalar::from_u128(b_val);
     let C = x * A + r * B;
-    let D = z * A + s * B;
 
-    let instance = proof::Instance { C, D, A, B, a, b };
-    let witness = proof::Witness { x, z, r, s };
+    let instance = proof::Instance { C, A, B, a, b };
+    let witness = proof::Witness { x, r };
 
     let proof = proof::prove(&instance, &witness, b"pubscalars_or_test", &mut rng)?;
     proof::verify(&instance, &proof, b"pubscalars_or_test")