Program:
    (statements+=Statement)*;

Statement:
    AssignmentStatement;
    
AssignmentStatement:
    Variable EqualOperator AdditionExpression; 
    
AdditionExpression:
    Number AdditionOperator Number;

AdditionOperator:
	AddOp="+";

EqualOperator:
	"=";	

Number:
	INT;
	
Variable:
	VAR;
	
terminal VAR:('a'..'z');    

ProjectName
    +

ProjectName
    +
      1
      2

ProjectName
    =
      x
      +
       1
       2  

corresponding to

  =
 / \
x   +
   / \
  1   2