parks-a-firing-whose-morph-operand-got-stuck.yaml

# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# yamllint disable rule:line-length
# The 'morph' of '$.a' gets stuck on 'L_none', which no entry answers. Under
# '--partial' the firing gets stuck right there, as it does without the
# option, so neither the 'morph' of '$.b' nor the join runs, and the site the
# fork stands at is parked. Before #2014 the operand came back as the term it
# was parked at and the entry went on as if it were morphed.
symbolic: |
  - λ: L_fork
    dataize:
      𝛿1: $.c
    morph:
      𝑛1: $.a
      𝑛2: $.b
    join:
      on: 𝛿1
      left: 𝑛1
      right: 𝑛2
location: 'Q.y'
partial: true
input: '⟦ y ↦ ⟦ c ↦ ⟦ λ ⤍ 𝜎1 ⟧, a ↦ ⟦ λ ⤍ L_none ⟧.x, b ↦ ⟦ Δ ⤍ 05- ⟧, λ ⤍ L_fork ⟧.φ ⟧'
result: '⟦ c ↦ ⟦ λ ⤍ 𝜎1 ⟧, a ↦ ⟦ λ ⤍ L_none ⟧.x, b ↦ ⟦ Δ ⤍ 05- ⟧, λ ⤍ L_fork ⟧.φ'
protocol: |
  𝕄(Φ.y):
    𝔼(L_fork):
      𝔻(ξ.c):
        𝛿·1·1 := 𝔻(𝜎1:λ)
      𝛿1·1 := 𝛿·1·1  # 𝔻(ξ.c)
      𝕄(ξ.a):
        unanswered L_none  # 𝕄(L_none:λ)
      stuck L_none