diff --git a/Cargo.lock b/Cargo.lock
index 29c1d96..d216c43 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -140,6 +140,7 @@ dependencies = [
  "ariadne",
  "chumsky",
  "clap",
+ "hir",
  "lexer",
  "parser",
 ]
@@ -159,6 +160,13 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "hir"
+version = "0.1.0"
+dependencies = [
+ "parser",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.8.0"
diff --git a/Cargo.toml b/Cargo.toml
index 1575ccd..338c470 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,4 +3,5 @@ members = [
     "crates/main",
     "crates/lexer",
     "crates/parser",
+    "crates/hir",
 ]
\ No newline at end of file
diff --git a/crates/hir/Cargo.toml b/crates/hir/Cargo.toml
new file mode 100644
index 0000000..178f2d3
--- /dev/null
+++ b/crates/hir/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "hir"
+license = "MIT OR Apache-2.0"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+parser = { path = "../parser" }
\ No newline at end of file
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
new file mode 100644
index 0000000..7b593c2
--- /dev/null
+++ b/crates/hir/src/lib.rs
@@ -0,0 +1,49 @@
+use std::ops::Range;
+use parser::Expr;
+
+#[derive(Debug)]
+pub enum Value { Int(i64), Float(f64), Bool(bool), String(String), Ident(String) }
+
+#[derive(Debug)]
+pub enum IRKind {
+    Define { name: String, type_hint: String, value: Box<Self> },
+    Fun { name: String, return_type_hint: String, args: Vec<(String, String)>, body: Box<Self> },
+    Call { name: String, args: Vec<Self> },
+    Do { body: Box<Self> },
+    If { cond: Box<Self>, body: Box<Self>, else_body: Box<Self> },
+    Value { value: Value },
+    Binary { op: String, left: Box<Self>, right: Box<Self> },
+}
+
+#[derive(Debug)]
+pub struct IR {
+    pub kind: IRKind,
+    pub span: Range<usize>
+}
+
+impl IR {
+    pub fn new(kind: IRKind, span: Range<usize>) -> Self {
+        Self { kind, span }
+    }
+}
+
+pub fn ast_to_ir(ast: Vec<(Expr, Range<usize>)>) -> Vec<IR> {
+    let mut irs = Vec::new();
+    for expr in ast {
+        let ir_kind = expr_to_ir(&expr.0);
+        let ir = IR::new(ir_kind, expr.1);
+        irs.push(ir);
+    }
+    irs
+}
+
+pub fn expr_to_ir(expr: &Expr) -> IRKind {
+    match expr {
+        Expr::Let { name, type_hint, value } => {
+            let value = expr_to_ir(&value.0);
+            IRKind::Define { name: name.clone(), type_hint: type_hint.clone(), value: Box::new(value) }
+        },
+        Expr::Int(value) => IRKind::Value { value: Value::Int(*value) },
+        _ => { dbg!(expr); todo!() }
+    }
+}
\ No newline at end of file
diff --git a/crates/main/Cargo.toml b/crates/main/Cargo.toml
index c338af3..cd63448 100644
--- a/crates/main/Cargo.toml
+++ b/crates/main/Cargo.toml
@@ -8,5 +8,6 @@ edition = "2021"
 clap = { version = "3.0.14", features = ["derive"] }
 lexer = { path = "../lexer" }
 parser = { path = "../parser" }
+hir = { path = "../hir" }
 chumsky = "0.8.0"
 ariadne = "0.1.5"
\ No newline at end of file
diff --git a/crates/main/src/main.rs b/crates/main/src/main.rs
index 14f5731..a606a54 100644
--- a/crates/main/src/main.rs
+++ b/crates/main/src/main.rs
@@ -4,6 +4,7 @@ use clap::Parser as ArgParser;
 use ariadne::{Report, ReportKind, Label, Source, Color, Fmt};
 use lexer::lex;
 use parser::parse;
+use hir::ast_to_ir;
 
 pub mod args;
 use args::{Args, Options};
@@ -25,6 +26,7 @@ fn main() {
             let (tokens, lex_error) = lex(src.clone());
             let (ast, parse_error) = parse(tokens.unwrap(), src.chars().count());
 
+            // Report errors.
             lex_error.into_iter()
                 .map(|e| e.map(|e| e.to_string()))
                 .chain(parse_error.into_iter().map(|e| e.map(|tok| tok.to_string())))
@@ -84,9 +86,6 @@ fn main() {
                                             .fg(Color::Red)
                                     ))
                                     .with_color(Color::Red)
-                            )
-                            .with_help(
-                                "You might have forgotten to end a previous line with semicolon"
                             ),
                         _ => {
                             println!("{:?}", e);
@@ -99,7 +98,11 @@ fn main() {
 
             match ast {
                 Some(ast) => {
-                    println!("{:#?}", ast);
+                    // Convert the AST to HIR.
+                    let ir = ast_to_ir(ast);
+
+                    // Print the HIR.
+                    println!("{:#?}", ir);
                 },
                 None => {
                     log(2, "Failed to parse.");
diff --git a/example/ex.hades b/example/ex.hades
index a403401..6f77848 100644
--- a/example/ex.hades
+++ b/example/ex.hades
@@ -1,17 +1 @@
--- Variables
-let foo: Int = 1;
-let bar: String = "bar";
-
--- Functions
-fun add (lhs: Int) (rhs: Int): Int = lhs + rhs;
-fun add_2 (lhs: Int) (rhs: Int): Int = do
-    let a: Int = lhs + rhs;
-    let b: Int = a + lhs;
-    return b;
-end;
-
--- Entry point (maybe)
-fun main: Void = do
-    print(add(34, 35));
-    return 0;
-end;
\ No newline at end of file
+let foo: int = 1;
\ No newline at end of file