Merge pull request #12 from guilhermgonzaga/master

Fix typos; Insert missing lines in README.md

README.md

@@ -1,6 +1,9 @@
 # What is calc?
 
 Calc is an interactive calculator which provides for easy large
+numeric calculations, but which also can be easily programmed
+for difficult or long calculations.	 It can accept a command line
+argument, in which case it executes that single command and exits.
 Otherwise, it enters interactive mode.  In this mode, it accepts
 commands one at a time, processes them, and displays the answers.
 In the simplest case, commands are simply expressions which are
@@ -16,7 +19,7 @@ and the calculator will print:
 15
 ```
 
-Calc as the usual collection of arithmetic operators +, -, /, * as
+Calc has the usual collection of arithmetic operators +, -, /, * as
 well as ^ (exponentiation), % (modulus) and // (integer divide).
 For example:
 

help/intro

@@ -15,7 +15,7 @@ What is calc?
 
     	    15
 
-    Calc as the usual collection of arithmetic operators +, -, /, *
+    Calc has the usual collection of arithmetic operators +, -, /, *
     as well as ^ (exponentiation), % (modulus) and // (integer divide).
     For example:
 
@@ -137,7 +137,7 @@ What is calc?
 
 	    f2(79)
 
-    will produce;
+    will produce:
 
 	    1009847364737869270905302433221592504062302663202724609375
 
@@ -150,7 +150,7 @@ What is calc?
 
 	    sc(31, 61)
 
-    will produce;
+    will produce:
 
 	    256772