ibc i (IBCFunctionErrorHandler fn a n) f =
  return f { ibc_function_errorhandlers = (fn, a, n) : ibc_function_errorhandlers f }
ibc i (IBCFunctionErrorHandler fn a n) f =
  return f { ibc_function_errorhandlers = (fn, a, n) : ibc_function_errorhandlers f }
ibc i (IBCFunctionErrorHandler fn a n) f =
  return f { ibc_function_errorhandlers = (fn, a, n) : ibc_function_errorhandlers f }