Your observation that categories are used in FRP is correct. Haskell's Yampa is built on top of Arrows that is an extension of categories: https://wiki.haskell.

Your observation that categories are used in FRP is correct. Haskell's Yampa is built on top of Arrows that is an extension of categories: https://wiki.haskell.org/Yampa https://wiki.haskell.org/Yampa