parks-a-firing-whose-deferred-argument-got-stuck.yaml

# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# yamllint disable rule:line-length
# A 'defer' line works out every argument of a copy that is no bare symbol
# before it writes the call. Here the argument 'x' fires 'L_outer', whose
# operand gets stuck on 'L_none'. Under '--partial' the firing of 'L_pair'
# gets stuck right there, so no 'deferred' line is written and the site of
# 'L_pair' is parked. Before #2014 the argument was kept as written and the
# entry went on as if it were worked out.
symbolic: |
  - λ: L_outer
    dataize:
      𝛿1: ξ.arg
    𝑛: ⟦ λ ⤍ 𝜎 ⟧
  - λ: L_pair
    morph:
      𝑛1: $.c
    defer:
      𝑛2: 𝑛1
    𝑛: 𝑛2
location: 'Q.p'
partial: true
input: >
  ⟦ box ↦ ⟦ s ↦ ∅, x ↦ ∅, φ ↦ ξ.s.next ⟧,
    p ↦ ⟦
      c ↦ Φ.box( ⟦ λ ⤍ 𝜎1 ⟧, ⟦ arg ↦ ⟦ λ ⤍ L_none ⟧, λ ⤍ L_outer ⟧.φ ),
      λ ⤍ L_pair ⟧.φ ⟧
result: '⟦ c ↦ Φ.box( ⟦ λ ⤍ 𝜎1 ⟧, ⟦ arg ↦ ⟦ λ ⤍ L_none ⟧, λ ⤍ L_outer ⟧.φ ), λ ⤍ L_pair ⟧.φ'
protocol: |
  𝕄(Φ.p):
    𝔼(L_pair):
      𝕄(ξ.c):
        𝑛·1·1 := Φ.box( s ↦ 𝜎1:λ )
        𝑛·1·2 := 𝑛·1·1( x ↦ ⟦ arg ↦ L_none:λ, λ ⤍ L_outer ⟧.φ )
        morphed 𝑛·1·3 := 𝑛·1·2
      𝑛1·1 := 𝑛·1·3  # 𝕄(ξ.c)
      𝕄(𝑛1.x):
        𝔼(L_outer):
          𝔻(ξ.arg):
            unanswered L_none  # 𝔻(L_none:λ)
          stuck L_none
      stuck L_none