intro γ_in δ_in
γ : Program
δ : List Program
α : Program
ℓ : TP α
⊢ γ ∈ δ →
    δ ∈ P α ℓ →
      if isAtomic α = true then γ = α
      else if isStar α = true then lengthOfProgram γ ≤ lengthOfProgram α else lengthOfProgram γ < lengthOfProgram α
γ : Program
δ : List Program
α : Program
ℓ : TP α
γ_in : γ ∈ δ
δ_in : δ ∈ P α ℓ
⊢ if isAtomic α = true then γ = α
  else if isStar α = true then lengthOfProgram γ ≤ lengthOfProgram α else lengthOfProgram γ < lengthOfProgram α