Can't make an ADT where the field is an arrow type.

[NoamDev]

Reproducing the behavior

Running command bend run-c main.bend With code

type Fun:
  nat2nat {f: u24->u24}

def main:
  return 1

Error:

Errors:
In main.bend :
- expected: ','
- detected:
  2 |   nat2nat {f: u24->u24}

Expected behavior: This should check.

System Settings

Example:

• Bend: bend-lang 0.2.37-alpha.1 built from branch 615-add-progressive-typing-to-bend Last commit in that branch at the time of writing: https://github.com/HigherOrderCO/Bend/commit/eaa2809a0c066b2ebc129dca89354435d1cebd17

Additional context

No response