Method app

crates/common/src/env.rs:871–877

Constructs a function application `f a`.

(f: Expr, a: Expr)

    let mut hasher = blake3::Hasher::new();
    hasher.update(&[ESORT]);
    hasher.update(x.get_hash().as_bytes());
    Expr(Arc::new(ExprData::Sort(x, hasher.finalize())))
  }

  /// Constructs a constant reference with universe level arguments.
  pub fn cnst(x: Name, us: Vec<Level>) -> Self {
    let mut hasher = blake3::Hasher::new();
    hasher.update(&[EREF]);
    hasher.update(x.get_hash().as_bytes());
    for u in &us {