+ - +
_____[05]______[3]______
//////////////////
___________(1)__________
///////////////////
x ∈ (1 ; 3]
2 + 3 = 5
+ - +
_____[05]______[3]______
//////////////////
___________(1)__________
///////////////////
x ∈ (1 ; 3]
2 + 3 = 5