code: def receipt(df):
      
      mutated_df = df[['IdPRONAC', 'idPlanilhaItem']].astype(str)
      mutated_df['pronac_planilha_itens'] = (
          f"{mutated_df['IdPRONAC']}/{mutated_df['idPlanilhaItem']}"
      )
  
      return (
          mutated_df
          .set_index(['pronac_planilha_itens'])
      )
docs: Return a dataframe to verify if a item has a receipt.