add exceptions example and explanation

1 files changed, 28 insertions, 3 deletions

diff --git a/Exceptions/README.md b/Exceptions/README.md
index df654d3..9350a28 100644
--- a/Exceptions/README.md
+++ b/Exceptions/README.md
@@ -6,14 +6,39 @@ The example in this section is a derivative of the function reference summary in
 
 ## Source
 
-### 
+### exceptions.b:17,26
 
+This section calculates numbers within the fibonacci sequence to a given interval. In this case, the first 5 numbers are calculated within the sequence.
 
+Note the call to the `raise` keyword after the fibonacci calculations have completed, but before the program exits.
 
-## Demo
+### exceptions.b:31,47
+
+The `fibonacci()` function attempts to perform a `fib()` call and, if an exception `e` is thrown, attempts to handle the exception in a manner depending on the exception type. 
+
+Note that the attempted operation is wrapped in a `{ ... }` block.
+
+### exceptions.b:49,63
 
+The `raises` clause allows for warnings to be generated for un-caught exception potential within a program. Note that these exception types can be user-defined. 
+
+The `FIB` exception type is defined at: exceptions.b:12
+
+## Demo
 
+	; limbo exceptions.b
+	; exceptions
+	F(0) = 1
+	F(1) = 1
+	F(2) = 2
+	F(3) = 3
+	F(4) = 5
+	sh: 798 "Exceptions":going down!
+	; 
 
 ## Exercises
 
-- 
+- Try removing the raise for "going down!".
+- Remove the `i < 5` portion of the for loop, how many values are printed and why?
+- Try removing the exception-catching block from around calls to `fib()`, do you get warnings?
+- Try changing the raise type within `fib()`, does `fibonacci()` handle the exception `e` differently?