EL operators

Arithmetic (5)

Addition:   +

Subtraction:  -

Multiplication:  *

Division:   / and div
(You can divide by zero in EL, there you get infinity not an Error)

Remainder:   % and mod
You cannot use remainder operator against zero, there you get an exception


Logical (3)

AND: && and and

OR: || and or


NOT: ! and not

Relational (6)

Equals: == and eq

Not equals: != and ne

Less than: < and lt

Greater than: > and gt

Less than or equal to: <= and le

Greater than or equal to: >= and ge

Don’t use EL reserved ! words as Identifiers

true/false : boolean literals

null : It means null

instanceof  : reserved for future

empty : an operator to check something is null or empty. 
eg. $(empty A) returns true if A is empty.

Notes:
In arithmetic, EL treats the null value as “zero”. In logical expressions, EL treats the null value as “false”.