
# PAL (Modelos de lenguaje asistidos por programa)

import { Callout, FileTree } from 'nextra-theme-docs'
import {Screenshot} from 'components/screenshot'
import PAL from '../../img/pal.png'

[Gao et al., (2022)](https://arxiv.org/abs/2211.10435) presenta un método que utiliza LLMs para leer problemas en lenguaje natural y generar programas como pasos intermedios de razonamiento. Llamado modelos de lenguaje asistidos por programa (PAL), difiere del prompting en cadena de pensamiento en que, en lugar de utilizar texto libre para obtener una solución, desplaza el paso de la solución a un tiempo de ejecución programático, como un intérprete de Python.

<Screenshot src={PAL} alt="PAL" />
Image Source: [Gao et al., (2022)](https://arxiv.org/abs/2211.10435)

Veamos un ejemplo utilizando LangChain y OpenAI GPT-3. Estamos interesados en desarrollar una aplicación simple que sea capaz de interpretar la pregunta formulada y proporcionar una respuesta aprovechando el intérprete de Python.

Específicamente, estamos interesados en crear una funcionalidad que permita el uso del LLM para responder preguntas que requieren comprensión de fechas. Proporcionaremos al LLM una indicación que incluye algunos ejemplos adoptados de [aquí](https://github.com/reasoning-machines/pal/blob/main/pal/prompt/date_understanding_prompt.py).

Estos son los imports que necesitamos:

```python
import openai
from datetime import datetime
from dateutil.relativedelta import relativedelta
import os
from langchain.llms import OpenAI
from dotenv import load_dotenv
```

Configuremos primeros algunas cosas:

```python
load_dotenv()

# API configuration
openai.api_key = os.getenv("OPENAI_API_KEY")

# for LangChain
os.environ["OPENAI_API_KEY"] = os.getenv("OPENAI_API_KEY")
```

Configuremos la instancia del modelo

```python
llm = OpenAI(model_name='text-davinci-003', temperature=0)
```

Configuremos el prompt y la pregunta:

```python
question = "Today is 27 February 2023. I was born exactly 25 years ago. What is the date I was born in MM/DD/YYYY?"

DATE_UNDERSTANDING_PROMPT = """
# Q: 2015 is coming in 36 hours. What is the date one week from today in MM/DD/YYYY?
# If 2015 is coming in 36 hours, then today is 36 hours before.
today = datetime(2015, 1, 1) - relativedelta(hours=36)
# One week from today,
one_week_from_today = today + relativedelta(weeks=1)
# The answer formatted with %m/%d/%Y is
one_week_from_today.strftime('%m/%d/%Y')
# Q: The first day of 2019 is a Tuesday, and today is the first Monday of 2019. What is the date today in MM/DD/YYYY?
# If the first day of 2019 is a Tuesday, and today is the first Monday of 2019, then today is 6 days later.
today = datetime(2019, 1, 1) + relativedelta(days=6)
# The answer formatted with %m/%d/%Y is
today.strftime('%m/%d/%Y')
# Q: The concert was scheduled to be on 06/01/1943, but was delayed by one day to today. What is the date 10 days ago in MM/DD/YYYY?
# If the concert was scheduled to be on 06/01/1943, but was delayed by one day to today, then today is one day later.
today = datetime(1943, 6, 1) + relativedelta(days=1)
# 10 days ago,
ten_days_ago = today - relativedelta(days=10)
# The answer formatted with %m/%d/%Y is
ten_days_ago.strftime('%m/%d/%Y')
# Q: It is 4/19/1969 today. What is the date 24 hours later in MM/DD/YYYY?
# It is 4/19/1969 today.
today = datetime(1969, 4, 19)
# 24 hours later,
later = today + relativedelta(hours=24)
# The answer formatted with %m/%d/%Y is
today.strftime('%m/%d/%Y')
# Q: Jane thought today is 3/11/2002, but today is in fact Mar 12, which is 1 day later. What is the date 24 hours later in MM/DD/YYYY?
# If Jane thought today is 3/11/2002, but today is in fact Mar 12, then today is 3/12/2002.
today = datetime(2002, 3, 12)
# 24 hours later,
later = today + relativedelta(hours=24)
# The answer formatted with %m/%d/%Y is
later.strftime('%m/%d/%Y')
# Q: Jane was born on the last day of Feburary in 2001. Today is her 16-year-old birthday. What is the date yesterday in MM/DD/YYYY?
# If Jane was born on the last day of Feburary in 2001 and today is her 16-year-old birthday, then today is 16 years later.
today = datetime(2001, 2, 28) + relativedelta(years=16)
# Yesterday,
yesterday = today - relativedelta(days=1)
# The answer formatted with %m/%d/%Y is
yesterday.strftime('%m/%d/%Y')
# Q: {question}
""".strip() + '\n'
```

```python
llm_out = llm(DATE_UNDERSTANDING_PROMPT.format(question=question))
print(llm_out)
```

```python
exec(llm_out)
print(born)
```

Esto producirá la siguiente salida: `02/27/1998`
