nf-on-phi.yaml

# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# PHI left normalization for morphing (#973), so dispatching an absent
# attribute on a φ-decorated formation no longer reduces under 𝒩 — it is now a
# stuck normal form. (Before #973 the PHI rule could fire on '!e1', so it was
# not a normal form; this pack was 'not-nf-on-phi'.)
expression: '[[ x -> [[ @ -> [[ ]] ]].y  ]]'
pattern: '[[ x -> !e1 ]]'
condition:
  nf: '!e1'