concurrency.md

@@ -56,7 +56,7 @@ in a letter, eg. 1.2.a, indicates a possible choice for question 1.2.
 
 ### 1. Cooperative or preemptive concurrency?
 
-**1.a.** The spec requires cooperative concurrency, preemption is
+**Choice 1.a.** The spec requires cooperative concurrency, and preemption is
 allowed as an extension.  Both would be specified precisely in
 terms of what progress and fairness guarantees the programmer can
 expect.
@@ -83,7 +83,7 @@ expect.
 - Long-running pure code must be refactored into the IO monad so
   that explicit yield points can be inserted.
 
-**1.b.** Preemption is required by the spec.
+**Choice 1.b.** Preemption is required by the spec.
 
 **Pros**
 
@@ -121,7 +121,7 @@ expect.
 
 **2.1.** choices for concurrent calls:
 
-**2.1.a.** we annotate concurrent calls:
+**Choice 2.1.a.** we annotate concurrent calls:
 
 > **a.** concurrent
 > **b.** mayblock
@@ -147,7 +147,7 @@ expect.
 > concurrently with other threads is a choice the programmer can
 > reasonably make.
 
-**2.1.b.** we annotate non concurrent calls:
+**Choice 2.1.b.** we annotate non concurrent calls:
 
 > **Rationale** for annotating the non-concurrent calls: this is a
 > performance issue.  It is always correct to make a concurrent
@@ -196,12 +196,12 @@ We have a choice when it comes to `IORef`s, however.  (Note that
 this only affects true multiprocessor implementations of concurrent
 Haskell).
 
-**3.a** Specify a weak memory model, in which `IORef` updates
+**Choice 3.a** Specify a weak memory model, in which `IORef` updates
 may be observed out of order, but specify that certain operations
 (eg. `MVar` operations) constitute sequence points around which no
 re-ordering may happen.
 
-**3.b** Specify a strong memory model in which no re-ordering is
+**Choice 3.b** Specify a strong memory model in which no re-ordering is
 observable.
 
 **Pros**