Ch6 - elaborate Action rules

Author: gomain

text/chapter6.md

@@ -624,12 +624,12 @@ Another reason to define a superclass relationship is in the case where there is
        act :: m -> a -> a
      ```
 
-     An _action_ is a function which describes how monoidal values can be used to modify a value of another type. There are two laws for the `Action` type class:
+     An _action_ is a function which describes how monoidal values are used to determine how to modify a value of another type. There are two laws for the `Action` type class:
 
      - `act mempty a = a`
      - `act (m1 <> m2) a = act m1 (act m2 a)`
 
-     That is, the action respects the operations defined by the `Monoid` class.
+     Applying an empty action is a no-op. And applying two actions in sequence is the same as applying the actions combined. That is, actions respect the operations defined by the `Monoid` class.
 
      For example, the natural numbers form a monoid under multiplication: