 
 
 
==, !=, >, >=, <, =< are infixed operators.
a==b tests the equality between a and b and returns 1 
if a is equal to b and 0 otherwise.
a!=b returns 1 if a and b are different and 0 
otherwise.
 a>=b returns 1 if a is superior or equal to b 
and 0 otherwise.
a>b returns 1 if a is strictly superior to b
and 0 otherwise.
a<=b returns 1 if a is inferior or equal to b and 
0 otherwise.
a<b returns 1 if a is strictly inferior to b 
and 0 otherwise.
To write an algebraic function having the same result as an 
if...then...else, we use the boolean function ifte.
For example : 
defines the boolean function f such that f(x)= true if 
x ∈ ]0;+∞[ and f(x)=false if x ∈ ]−∞;0].
Input :
Output :
Look out !
a=b is not a boolean !!!!
a==b is a boolean.
 
 
