Update README

README.md

@@ -33,7 +33,7 @@ and values are of `Any` type.
 
 Once a `Bijection`, `b`, is created, we add a new key-value pair in
 the same manner as with a `Dict`:
-```julia
+```
 julia> b[1] = "hello"
 "hello"
 
@@ -42,20 +42,20 @@ julia> b[2] = "bye"
 ```
 Notice, however, that if we add a new key with a value that already
 exists in the `Bijection` an error ensues:
-```julia
+```
 julia> b[3] = "hello"
 ERROR: One of x or y already in this Bijection
 ```
 Likewise, if a key already has a value it cannot be changed by giving
 it a new value:
-```julia
+```
 julia> b[1] = "ciao"
 ERROR: One of x or y already in this Bijection
 ```
 
 If we wish to change the value associated with a given key, the pair
 must first be deleted using `delete!`:
-```julia
+```
 julia> delete!(b,1)
 Bijection{Any,Any} (with 1 pairs)
 
@@ -67,7 +67,7 @@ julia> b[1] = "ciao"
 
 To access a value associated with a given key, we use the same syntax
 as for a `Dict`:
-```julia
+```
 julia> b[1]
 "ciao"
 
@@ -76,7 +76,7 @@ julia> b[2]
 ```
 
 If the key is not in the `Bijection` an error is raised:
-```julia
+```
 julia> b[3]
 ERROR: KeyError: 3 not found
 ```
@@ -85,7 +85,7 @@ Since the values in a `Bijection` must be distinct, we can give a
 value as an input and retrieve its associate key. The function
 `inverse(b,y)` finds the value `x` such that `b[x]==y`. However, we
 provide the handy short cut `b(y)`:
-```julia
+```
 julia> b("bye")
 2
 
@@ -95,7 +95,7 @@ julia> b("ciao")
 
 Naturally, if the requested value is not in the `Bijection` an error
 is raised:
-```julia
+```
 julia> b("hello")
 ERROR: KeyError: hello not found
 ```
@@ -167,7 +167,7 @@ Thinking of a `Bijection` as a mapping between finite sets, we
 provide the functions `domain` and `image`. These return,
 respectively, the set of keys and the set of values of the
 `Bijection`.
-```julia
+```
 julia> domain(b)
 Set(Any[2,1])
 
@@ -177,22 +177,22 @@ Set(Any["bye","ciao"])
 
 The `collect` function returns the `Bijection` as an array of
 key-value pairs:
-```julia
+```
 julia> collect(b)
 2-element Array{Tuple{Any,Any},1}:
  (2,"bye")
  (1,"ciao")
 ```
 
 The `length` function returns the number of key-value pairs:
-```julia
+```
 julia> length(b)
 2
 ```
 
 The `isempty` function returns `true` exactly when the `Bijection`
 contains no pairs:
-```julia
+```
 julia> isempty(b)
 false
 ```