README.md in dentaku-2.0.7 vs README.md in dentaku-2.0.8

@@ -55,11 +55,11 @@
 #=> 11
 calculator.evaluate('(5 + 3) * 2')
 #=> 16
 ```
 
-The `evalutate` method will return `nil` if there is an error in the formula.
+The `evaluate` method will return `nil` if there is an error in the formula.
 If this is not the desired behavior, use `evaluate!`, which will raise an
 exception.
 
 ```ruby
 calculator.evaluate('10 * x')
@@ -121,16 +121,20 @@
 application, AST caching will consume more memory with each new formula.
 
 BUILT-IN OPERATORS AND FUNCTIONS
 ---------------------------------
 
-Math: `+ - * / %`
+Math: `+`, `-`, `*`, `/`, `%`
 
-Logic: `< > <= >= <> != = AND OR`
+Logic: `<`, `>`, `<=`, `>=`, `<>`, `!=`, `=`, `AND`, `OR`
 
-Functions: `IF NOT MIN MAX ROUND ROUNDDOWN ROUNDUP`
+Functions: `IF`, `NOT`, `MIN`, `MAX`, `ROUND`, `ROUNDDOWN`, `ROUNDUP`
 
-Math: all functions from Ruby's Math module, including `SIN, COS, TAN, ...`
+Selections: `CASE` (syntax see [spec](https://github.com/rubysolo/dentaku/blob/master/spec/calculator_spec.rb#L292))
+
+Math: all functions from Ruby's Math module, including `SIN`, `COS`, `TAN`, etc.
+
+String: `LEFT`, `RIGHT`, `MID`, `LEN`, `FIND`, `SUBSTITUTE`, `CONCAT`
 
 RESOLVING DEPENDENCIES
 ----------------------
 
 If your formulas rely on one another, they may need to be resolved in a