{P : Sort u} →
  {ref optIdent cond thenBranch elseBranch ref' optIdent' cond' thenBranch' elseBranch' : Lean.Syntax} →
    { ref := ref, optIdent := optIdent, cond := cond, thenBranch := thenBranch, elseBranch := elseBranch } =
        { ref := ref', optIdent := optIdent', cond := cond', thenBranch := thenBranch', elseBranch := elseBranch' } →
      (ref = ref' → optIdent = optIdent' → cond = cond' → thenBranch = thenBranch' → elseBranch = elseBranch' → P) → P