Starts a good tracing interface

src/prover/constraints.rs

@@ -5,6 +5,7 @@ use litemap::LiteMap;
 use crate::ast::Body;
 use crate::ast::Predicate;
 use crate::ast::Variable;
+use crate::prover::tracing::colored_var;
 
 #[derive(Clone, Debug)]
 pub struct Constraints
@@ -187,7 +188,7 @@ impl Display for Constraints
         let len = self.set.len();
         for (i, (var, pred)) in self.set.iter().enumerate()
         {
-            write!(f, "{} = {}", var, pred)?;
+            write!(f, "{} = {}", colored_var(var), pred)?;
             if i != len - 1
             {
                 write!(f, ", ")?;