reduces-the-branches-of-a-fork-through-morphing.yaml

# SPDX-FileCopyrightText: Copyright (c) 2025 Objectionary.com
# SPDX-License-Identifier: MIT
---
# yamllint disable rule:line-length
# A branch is where a 'morph' operand earns its place: the condition comes
# down through 𝔻 and answers a symbol nobody has decided, both branches reach
# a normal form through 𝕄, a call of 'plus' nobody has fired, an 'evaluate'
# line fires each of them (#1874), and the answer is the first. Every line of
# the firing points back at the line that minted the symbol it carries, which
# is how the dependencies between firings are read. The dispatch of φ that
# ends the program is what fires the fork.
symbolic: |
  - λ: L_number_gt
    dataize:
      𝛿1: $.ρ
      𝛿2: $.x
    𝑛: Φ.bool( φ ↦ ⟦ λ ⤍ 𝜎 ⟧ )
  - λ: L_number_plus
    dataize:
      𝛿1: $.ρ
      𝛿2: $.x
    𝑛: Φ.number( φ ↦ ⟦ λ ⤍ 𝜎 ⟧ )
  - λ: L_fork
    dataize:
      𝛿1: $.ρ
    morph:
      𝑛1: $.then
      𝑛2: $.else
    evaluate:
      𝑛3: 𝑛1
      𝑛4: 𝑛2
    𝑛: 𝑛3
location: 'Q.@'
input: >
  ⟦ bytes(φ) ↦ ⟦⟧,
    bool(φ) ↦ ⟦ if ↦ ⟦ ρ ↦ ∅, then ↦ ∅, else ↦ ∅, λ ⤍ L_fork ⟧ ⟧,
    number(φ) ↦ ⟦
      gt(ρ, x) ↦ ⟦ λ ⤍ L_number_gt ⟧,
      plus(ρ, x) ↦ ⟦ λ ⤍ L_number_plus ⟧ ⟧,
    @ ↦ 5.gt( 0 ).if( 1.plus( 2 ), 3.plus( 4 ) ).φ ⟧
result: '𝜎2:λ'
protocol: |
  𝕄(Φ.φ):
    𝑛·0·1 := 5
    𝑛·0·2 := 𝑛·0·1.gt( x ↦ 0 )
    𝔼(L_number_gt):
      𝔻(Φ.a🌵0):
        𝕄(Φ.a🌵0):
          𝑛·1·1 := 5
          𝑛·1·2 := Φ.bytes( φ ↦ 40-14-00-00-00-00-00-00:Δ )
        𝛿·1·1 := 40-14-00-00-00-00-00-00  # 5.0
      𝛿1·1 := 𝛿·1·1  # 𝔻(ξ.ρ)
      𝔻(Φ.a🌵1):
        𝕄(Φ.a🌵1):
          𝑛·1·3 := 0
          𝑛·1·4 := Φ.bytes( φ ↦ 00-00-00-00-00-00-00-00:Δ )
        𝛿·1·2 := 00-00-00-00-00-00-00-00  # 0.0
      𝛿2·1 := 𝛿·1·2  # 𝔻(ξ.x)
      𝑛·1·5 := Φ.bool( φ ↦ 𝜎1:λ )  # 𝑛
      𝕄(𝑛·1·5):
        𝑛·1·6 := Φ.bool( φ ↦ 𝜎1:λ )
      𝑛·1·7 := 𝑛·1·6  # 𝕄(𝑛·1·5)
    𝑛·0·3 := 𝑛·1·6.if( then ↦ 1.plus( 2 ) )
    𝑛·0·4 := 𝑛·0·3( else ↦ 3.plus( 4 ) )
    𝔼(L_fork):
      𝔻(Φ.a🌵2):
        𝕄(Φ.a🌵2):
          𝑛·2·1 := Φ.bool( φ ↦ 𝜎1:λ )
      𝛿1·2 := 𝔻(𝜎1:λ)  # 𝔻(ξ.ρ)
      𝕄(Φ.a🌵3):
        𝑛·2·2 := 1
        𝑛·2·3 := 𝑛·2·2.plus( x ↦ 2 )
      𝑛1·2 := 𝑛·2·3  # 𝕄(ξ.then)
      𝕄(Φ.a🌵4):
        𝑛·2·4 := 3
        𝑛·2·5 := 𝑛·2·4.plus( x ↦ 4 )
      𝑛2·2 := 𝑛·2·5  # 𝕄(ξ.else)
      𝔼(L_number_plus):  # 𝔼(𝑛1)
        𝔻(Φ.a🌵5):
          𝕄(Φ.a🌵5):
            𝑛·3·1 := 1
            𝑛·3·2 := Φ.bytes( φ ↦ 3F-F0-00-00-00-00-00-00:Δ )
          𝛿·3·1 := 3F-F0-00-00-00-00-00-00  # 1.0
        𝛿1·3 := 𝛿·3·1  # 𝔻(ξ.ρ)
        𝔻(Φ.a🌵6):
          𝕄(Φ.a🌵6):
            𝑛·3·3 := 2
            𝑛·3·4 := Φ.bytes( φ ↦ 40-00-00-00-00-00-00-00:Δ )
          𝛿·3·2 := 40-00-00-00-00-00-00-00  # 2.0
        𝛿2·3 := 𝛿·3·2  # 𝔻(ξ.x)
        𝑛·3·5 := Φ.number( φ ↦ 𝜎2:λ )  # 𝑛
        𝕄(𝑛·3·5):
          𝑛·3·6 := Φ.number( φ ↦ 𝜎2:λ )
        𝑛·3·7 := 𝑛·3·6  # 𝕄(𝑛·3·5)
      𝑛3·2 := 𝑛·3·7  # 𝔼(𝑛1)
      𝔼(L_number_plus):  # 𝔼(𝑛2)
        𝔻(Φ.a🌵7):
          𝕄(Φ.a🌵7):
            𝑛·4·1 := 3
            𝑛·4·2 := Φ.bytes( φ ↦ 40-08-00-00-00-00-00-00:Δ )
          𝛿·4·1 := 40-08-00-00-00-00-00-00  # 3.0
        𝛿1·4 := 𝛿·4·1  # 𝔻(ξ.ρ)
        𝔻(Φ.a🌵8):
          𝕄(Φ.a🌵8):
            𝑛·4·3 := 4
            𝑛·4·4 := Φ.bytes( φ ↦ 40-10-00-00-00-00-00-00:Δ )
          𝛿·4·2 := 40-10-00-00-00-00-00-00  # 4.0
        𝛿2·4 := 𝛿·4·2  # 𝔻(ξ.x)
        𝑛·4·5 := Φ.number( φ ↦ 𝜎3:λ )  # 𝑛
        𝕄(𝑛·4·5):
          𝑛·4·6 := Φ.number( φ ↦ 𝜎3:λ )
        𝑛·4·7 := 𝑛·4·6  # 𝕄(𝑛·4·5)
      𝑛4·2 := 𝑛·4·7  # 𝔼(𝑛2)
      𝑛·2·6 := 𝑛3·2  # 𝑛
      𝑛·2·7 := 𝑛3·2  # 𝕄(𝑛·2·6)