Method lam

crates/common/src/env.rs:880–888

Constructs a lambda abstraction `fun (n : t) => b`.

(n: Name, t: Expr, b: Expr, bi: BinderInfo)

    hasher.update(&[EREF]);
    hasher.update(x.get_hash().as_bytes());
    for u in &us {
      hasher.update(u.get_hash().as_bytes());
    }
    Expr(Arc::new(ExprData::Const(x, us, hasher.finalize())))
  }

  /// Constructs a function application `f a`.
  pub fn app(f: Expr, a: Expr) -> Self {
    let mut hasher = blake3::Hasher::new();
    hasher.update(&[EAPP]);
    hasher.update(f.get_hash().as_bytes());
    hasher.update(a.get_hash().as_bytes());