∀ {pu : Lean.Compiler.LCNF.Purity} (decl : Lean.Compiler.LCNF.FunDecl pu)
  (h : autoParam (pu = Lean.Compiler.LCNF.Purity.pure) Lean.Compiler.LCNF.CodeDecl._auto_1),
  sizeOf (Lean.Compiler.LCNF.CodeDecl.fun decl h) = 1 + sizeOf decl + sizeOf h