Method arbitrary

crates/ixon/src/expr.rs:303–305

(g: &mut Gen)

          stack.push(f_ptr);
        },
        Case::Lam => {
          let uses = match gen_range(g, 0..4) {
            0 => Uses::Erased,
            1 => Uses::Linear,
            2 => Uses::Affine,
            _ => Uses::Many,