Typos

Author: Froussios

Part 3 - Taming the sequence/7. Custom operators.md

@@ -179,7 +179,7 @@ Every Rx operator, internally, does 3 things
 2. Transforms the observed sequence according to the operator's purpose.
 3. Pushes the modified sequence to its own subscribers, by calling `onNext`, `onError` and `onCompleted`.
 
-The `compose` operator works with a method that makes an observable out of another. By doing this, it spares you the trouble of doing the 3 steps above manually. That presumes that you can do the transformation by using existing operators. If the operators don't already exist, or if you think you can get better performance manually, you need to receive items manually, process them and re-push them. An `Observable.Transformer` that does this would include a `Subscribe` to the source `Observable` and the creation of a new `Observable`, possibly a `Subject`. As an exercise, you can try implementing an operator (e.g. reimplement `map`) without using any existing operators.
+The `compose` operator works with a method that makes an observable out of another. By doing this, it spares you the trouble of doing the 3 steps above manually. That presumes that you can do the transformation by using existing operators. If the operators don't already exist, or if you think you can get better performance manually, you need to receive items manually, process them and re-push them. An `Observable.Transformer` that does this would include a `subscribe` to the source `Observable` and the creation of a new `Observable` to be returned, possibly a `Subject`. As an exercise, you can try implementing an operator (e.g. reimplement `map`) without using any existing operators.
 
 There's a simpler way. The `lift` operator is similar to `compose`. Instead of transforming `Observable`, it transforms `Subscriber`.