lean_workbook_plus_32250

⚠️ Retired — specification defect

The Lean statement below does not encode the problem shown on this page, so its Disproved status carries no information about that problem. Do not import this node or use it as a dependency.

We have \n$a_{6+6} = a_6 + a_6 + 36$ \n$a_{6+6} = 2(a_3 + a_3 + 9) + 36$ \n$a_{6+6} = 4(a_2 + a_1 + 2) + 54$ \n$a_{6+6} = 4(a_1 + a_1 + 1 + 3) + 54$ \n$a_{6+6} = 4(6) + 54$ \n$a_{6+6} = 24 + 54$ \n$a_{6+6} = 78$

Why this node was retired

The posted statement is

theorem lean_workbook_plus_32250  (a : ℕ → ℕ)
  (h₀ : a 6 = a 3 + a 3 + 9)
  (h₁ : a 3 = a 2 + a 1 + 2)
  (h₂ : a 2 = a 1 + a 1 + 1 + 3)
  (h₃ : a 1 = 6) :
  a 6 + a 6 + 36 = 78   :=  by sorry

The formalization wrongly treats a whole substituted bracket as the value of a₂ and takes its value6 as a₁.

The recorded counterexample refutes the statement as encoded. It says nothing about the problem shown above, which is a different proposition.

Proposed corrected statement

Restore the consistent source recurrence a(m+n)=a(m)+a(n)+mn and the intended initial value a(1)=1; then a(12)=78. If retaining the posted four hypotheses, the conclusion must instead be150.

Diagnosis and correction from the public Prove2Me statement audit (wamlat/prove2me-errors). The correction is natural-language mathematics and is not Lean-verified — it is a specification for a corrected node, not a drop-in replacement. No corrected replacement node exists yet.