[Compiler.inferBorrow] own _x.21: result of function call _x.21
[Compiler.inferBorrow] own _x.20: result of function call _x.20
[Compiler.inferBorrow] size: 3
    def f @&xs : tobj :=
      let _x.1 := 2;
      let _x.2 := List.lengthTR._redArg xs;
      let _x.3 := Nat.mul _x.1 _x.2;
      return _x.3