diff --git a/tree_inputs/src/lib.rs b/tree_inputs/src/lib.rs
index 688cb4241..18200a324 100644
--- a/tree_inputs/src/lib.rs
+++ b/tree_inputs/src/lib.rs
@@ -1,4 +1,5 @@
 pub mod ast;
+pub mod interpreter;
 pub mod schema;
 
 pub type Result = std::result::Result<(), egglog::Error>;
diff --git a/tree_inputs/src/schema.rs b/tree_inputs/src/schema.rs
index 033072694..2f0e37908 100644
--- a/tree_inputs/src/schema.rs
+++ b/tree_inputs/src/schema.rs
@@ -11,6 +11,7 @@ pub enum Type {
     TupleT(Vec<Rc<Type>>),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum BinaryOp {
     Add,
     Sub,
@@ -26,6 +27,7 @@ pub enum UnaryOp {
     Print,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Constant {
     Int(i64),
     Bool(bool),
@@ -43,11 +45,12 @@ pub enum Assumption {
     InLoop(RcExpr, RcExpr),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Expr {
     Const(Constant),
     Bop(BinaryOp, RcExpr, RcExpr),
     Uop(UnaryOp, RcExpr),
-    Get(RcExpr, i64),
+    Get(RcExpr, usize),
     Read(RcExpr, Type),
     Call(String, RcExpr),
     All(Order, Vec<RcExpr>),