diff --git a/src/circuit/num.rs b/src/circuit/num.rs
index 0bd801437..310bd9592 100644
--- a/src/circuit/num.rs
+++ b/src/circuit/num.rs
@@ -312,38 +312,6 @@ impl<E: Engine> AllocatedNum<E> {
         Ok((c, d))
     }
 
-    pub fn conditionally_negate<CS>(
-        &self,
-        mut cs: CS,
-        condition: &Boolean
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>
-    {
-        let r = Self::alloc(
-            cs.namespace(|| "conditional negation result"),
-            || {
-                let mut tmp = *self.value.get()?;
-                if *condition.get_value().get()? {
-                    tmp.negate();
-                }
-                Ok(tmp)
-            }
-        )?;
-
-        // (1-c)(x) + (c)(-x) = r
-        // x - 2cx = r
-        // (2x) * (c) = x - r
-
-        cs.enforce(
-            || "conditional negation",
-            |lc| lc + self.variable + self.variable,
-            |_| condition.lc(CS::one(), E::Fr::one()),
-            |lc| lc + self.variable - r.variable
-        );
-
-        Ok(r)
-    }
-
     pub fn get_value(&self) -> Option<E::Fr> {
         self.value
     }
@@ -433,107 +401,6 @@ mod test {
         }
     }
 
-    #[test]
-    fn test_num_conditional_negation() {
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::constant(true);
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            let mut negone = Fr::one();
-            negone.negate();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == negone);
-            assert!(n2.value.unwrap() == negone);
-            cs.set("conditional negation result/num", Fr::from_str("1").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::constant(false);
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == Fr::one());
-            assert!(n2.value.unwrap() == Fr::one());
-            cs.set("conditional negation result/num", Fr::from_str("2").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "condition"), Some(true)).unwrap()
-            );
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            let mut negone = Fr::one();
-            negone.negate();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == negone);
-            assert!(n2.value.unwrap() == negone);
-            cs.set("conditional negation result/num", Fr::from_str("1").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "condition"), Some(false)).unwrap()
-            );
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == Fr::one());
-            assert!(n2.value.unwrap() == Fr::one());
-            cs.set("conditional negation result/num", Fr::from_str("2").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "condition"), Some(false)).unwrap()
-            ).not();
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            let mut negone = Fr::one();
-            negone.negate();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == negone);
-            assert!(n2.value.unwrap() == negone);
-            cs.set("conditional negation result/num", Fr::from_str("1").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-        {
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::one())).unwrap();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "condition"), Some(true)).unwrap()
-            ).not();
-            let n2 = n.conditionally_negate(&mut cs, &b).unwrap();
-
-            assert!(cs.is_satisfied());
-            assert!(cs.get("conditional negation result/num") == Fr::one());
-            assert!(n2.value.unwrap() == Fr::one());
-            cs.set("conditional negation result/num", Fr::from_str("2").unwrap());
-            assert!(!cs.is_satisfied());
-        }
-    }
-
     #[test]
     fn test_num_nonzero() {
         {