message: Small corrections to writing-marble-tests.md
diff: @@ -26,7 +26,7 @@ The unit tests have helper methods that have been added to make creating tests e
  ### Ergonomic defaults for `hot` and `cold`
  -In both `hot` and `cold` methods, value charecters specified in marble diagrams are emitted as strings unless a `values`
  +In both `hot` and `cold` methods, value characters specified in marble diagrams are emitted as strings unless a `values`
  argument is passed to the method. Therefor:
  `hot('--a--b')` will emit `"a"` and `"b"` whereas
  @@ -43,13 +43,14 @@ Likewise, unspecified errors will just default to the string `"error"`, so:
  ## Marble Syntax
  Marble syntax is a string which represents events happening over "time". The first character of any marble string
  +
  always represents the "zero frame". A "frame" is somewhat analogous to a virtual millisecond.
  - `"-"` time: 10 "frames" of time passage.
  - `"|"` complete: The successful completion of an observable. This is the observable producer signaling `complete()`
  - `"#"` error: An error terminating the observable. This is the observable producer signaling `error()`
  -- `"a"` any character: All other characters represent a value being emitted by the producure signaling `next()`
  -- `"()"` sync groupings: When multiple events need to single in the same frame synchronously, parenthesis are used
  +- `"a"` any character: All other characters represent a value being emitted by the producer signaling `next()`
  +- `"()"` sync groupings: When multiple events need to be in the same frame synchronously, parentheses are used
  to group those events. You can group nexted values, a completion or an error in this manner. The position of the
  initial `(` determines the time at which its values are emitted.
  - `"^"` subscription point: (hot observables only) shows the point at which the tested observables will be subscribed
  @@ -71,7 +72,7 @@ always represents the "zero frame". A "frame" is somewhat analogous to a virtual
  `'-a-^-b--|'`: In a hot observable, on frame -20 emit `a`, then on frame 20 emit `b`, and on frame 50, `complete`.
  -`'--(abc)-|'`: on frame 20, emit `a`, `b`, and `c`, then on frame 80 `complete`
  +`'--(abc)-|'`: on frame 20, emit `a`, `b`, and `c`, then on frame 30 `complete`
  `'-----(a|)'`: on frame 50, emit `a` and `complete`.
  @@ -154,7 +155,7 @@ expectSubscriptions(y.subscriptions).toBe(ysubs);
  - Align the start of `xsubs` and `ysubs` diagrams with `expected` diagram.
  - Notice how the `x` cold observable is unsubscribed at the same time `e1` emits `y`.
  -In most tests it will be unnecessary to test subscription and unsubscription points, be either obvious or can be implied from the `expected` diagram. In those cases do not write subscription assertions. In test cases that have inner subscriptions or cold observables with multiple subscribers, these subscription assertions can be useful.
  +In most tests it will be unnecessary to test subscription and unsubscription points, being either obvious or implied from the `expected` diagram. In those cases do not write subscription assertions. In test cases that have inner subscriptions or cold observables with multiple subscribers, these subscription assertions can be useful.
  ## Generating PNG marble diagrams from tests
  