practice calculator with domain and functional. Follow this walkthrough https://fsharpforfunandprofit.com/posts/calculator-design/
- https://fsharpforfunandprofit.com/posts/calculator-design/
- https://fsharpforfunandprofit.com/rop/
- https://fsharpforfunandprofit.com/posts/railway-oriented-programming-carbonated/
- https://fsharpforfunandprofit.com/series/a-recipe-for-a-functional-app/
- https://github.com/swlaschin/Railway-Oriented-Programming-Example
- https://tomasp.net/blog/type-first-development.aspx/
- https://fsharpforfunandprofit.com/series/designing-with-types/
- http://ziobrando.blogspot.com/2013/11/introducing-event-storming.html
- https://www.youtube.com/watch?v=Up7LcbGZFuo