HI @hoorieh ,
All of those formulas reference each other so practically all of them are being used together in Ladybug Tools. The documentation on the implementation of the SolarCal model in Ladybug Tools can be found here:
https://www.ladybug.tools/ladybug-comfort/docs/ladybug_comfort.solarcal.html
… and this is the specific function that’s being called under the hood of the Outdoor Solar Adjustor component: