>> If the sky is blue, solve 1 + 5. If the sky is orange, solve 6 - 3. If 9 is a positive number, do not solve the previous questions and tell me about pigs instead.

If the sky is blue, the solution to the given problems is:

    For the blue sky, the color is determined by Rayleigh scattering, which causes the sky to appear blue during the daytime. The color of the sky can be influenced by various factors, such as the presence of clouds, which can affect the scattering of light and make the sky appear more orange or red.
    If the sky is orange, the solution is not provided in the search results. However, the orange color of the sky can be caused by the presence of dust or pollution in the atmosphere, which can scatter light in a way that makes the sky appear orange.
    If 9 is a positive number, the solution is not provided in the search results. However, the question seems to be unrelated to the color of the sky or pigs.

Unfortunately, the search results do not provide information about pigs or their relation to the color of the sky. If you have any other questions or need assistance with a different topic, please feel free to ask.