timowest

#1 
e1.or(e2).and(e3)) 

creates at first an 'or' operation based on e1 and e2 and uses this 'or' operation 
in a top level 'and' operation with e3 as the second operand.

Since 'and' has higher precedence than 'or' it is serialized as

(e1 or e2) and e3