Improved README.

README.md

@@ -26,18 +26,15 @@ pip install --upgrade pip
 
 Quant DSL is domain specific language for quantitative analytics in finance and trading.
 
-At the heart of Quant DSL is a set of elements (e.g. `Settlement`, `Fixing`, `Market`, `Wait`,
-`Choice`) which encapsulate maths used in finance and trading. The elements of the language can
-be freely composed into expressions of value.
-
+At the heart of Quant DSL is a set of elements (e.g. "Settlement", "Fixing", "Market", "Choice").
 The elements involve mathematical expressions commonly used within quantitative analytics, 
 such as: 
-[present value discounting](https://en.wikipedia.org/wiki/Present_value) for the `Settlement` element;
-[geometric Brownian motion](https://en.wikipedia.org/wiki/Geometric_Brownian_motion) for the `Market` element; and 
-[least squares Monte Carlo](https://en.wikipedia.org/wiki/Monte_Carlo_methods_for_option_pricing#Least_Square_Monte_Carlo)
-for the `Choice` element.
+[present value discounting](https://en.wikipedia.org/wiki/Present_value);
+[geometric Brownian motion](https://en.wikipedia.org/wiki/Geometric_Brownian_motion); and 
+[least squares Monte Carlo](https://en.wikipedia.org/wiki/Monte_Carlo_methods_for_option_pricing#Least_Square_Monte_Carlo).
 
-The validity of Monte Carlo simulation for all possible expressions in the language is
+The elements of the language can be freely composed into expressions of value. The validity of
+Monte Carlo simulation for all possible expressions in the language is
 [proven by induction](http://www.appropriatesoftware.org/quant/docs/quant-dsl-definition-and-proof.pdf).
 
 
@@ -63,8 +60,9 @@ The syntax of Quant DSL expressions is defined with
 
 ### Semantics
 
-Quant DSL expression `v` defines a function `[[v]](t)` from present time `t` to a random
-variable in a probability space. 
+In the definitions below, Quant DSL expression `v` defines a
+function `[[v]](t)` from present time `t` to a random
+variable in a probability space.
 
 
 ```
@@ -151,6 +149,7 @@ are discarded as soon as they are no longer required, such that memory usage is
 evaluation. For the delta calculations, nodes are selectively re-evaluated with perturbed values,
 according to the periods and markets they involve.
 
+
 ### calc()
 
 The examples below use the library function `calc()` to evaluate Quant DSL source code. It uses the methods of the