diff --git a/src/context.rs b/src/context.rs
index 326a1d4..d3761ff 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -142,10 +142,7 @@ impl<'a, T: ArenaObj> Ptr<T> {
 
 impl<T: ArenaObj> Clone for Ptr<T> {
     fn clone(&self) -> Ptr<T> {
-        Ptr {
-            idx: self.idx,
-            _dummy: PhantomData,
-        }
+        *self
     }
 }
 
diff --git a/src/dialects/builtin/ops.rs b/src/dialects/builtin/ops.rs
index 6273fec..229a5b5 100644
--- a/src/dialects/builtin/ops.rs
+++ b/src/dialects/builtin/ops.rs
@@ -254,11 +254,7 @@ impl Printable for ConstantOp {
         write!(
             f,
             "{} = {} {}",
-            self.get_operation()
-                .deref(ctx)
-                .get_result(0)
-                .unwrap()
-                .get_name(ctx),
+            self.get_result(ctx).get_name(ctx),
             self.get_opid().disp(ctx),
             self.get_value(ctx).disp(ctx)
         )
@@ -274,7 +270,7 @@ impl Verify for ConstantOp {
             });
         }
         let op = &*self.get_operation().deref(ctx);
-        if op.get_num_results() != 1 || op.get_num_operands() != 0 {
+        if op.get_num_operands() != 0 {
             return Err(CompilerError::VerificationError {
                 msg: "Incorrect number of results or operands".to_string(),
             });
diff --git a/src/printable.rs b/src/printable.rs
index 999819d..1370365 100644
--- a/src/printable.rs
+++ b/src/printable.rs
@@ -125,6 +125,10 @@ impl<'t, 'c, T: Printable> Display for Displayable<'t, 'c, T> {
 /// assert!(S { i: 0 }.print(&ctx, &state).to_string() == "0");
 /// let svec = vec![ S { i: 8 }, S { i: 16 } ];
 /// assert!(svec.iter().idisp(&ctx, ListSeparator::Char(',')).to_string() == "8,16");
+/// use pliron::{indented_block, printable::indented_nl};
+/// indented_block!(state, {
+///     assert_eq!(format!("{}{}", indented_nl(&state), S { i: 108 }.print(&ctx, &state)), "\n  108");
+/// });
 /// ```
 pub trait Printable {
     fn fmt(&self, ctx: &Context, state: &State, f: &mut fmt::Formatter<'_>) -> fmt::Result;