Syntax of  mathematical expressions
    
      --- Introduction ---
    
  
 
This module contains 10 exercises on the syntax of mathematic expressions.
Trained skills :
- to type an expression on the keyboard given a precise syntax ;
 
- to compose / decompose  a function with respect to usual reference functions ;
 
- to understand the  syntax  of an expression and to represent it with a tree ;
 
- to handle  different representations (formula, tree or sentence) of a same expression.