ConditionTest

(:A:a:) {$:A}
(:B:b:) {$:B}
(:C:c:) {$:C}
(:D:d:) {$:D}

 a
 b
 c
 d

(:if ( [ ! equal {$:A} z ] && [ ! equal {$:B} z ] ) || ( [ ! equal {$:C} z ] && [ ! equal {$:D} z ] ) :)
CONTENT
(:ifend:)

(:if ! equal {$:A} z :)
A ≠ z
(:ifend:)

A ≠ z

(:if [! equal {$:A} z] :)
A ≠ z
(:ifend:)

A ≠ z

(:if ( [! equal {$:A} z] && [ ! equal {$:B} z ] ) :)
A ≠ z and B ≠ z
(:ifend:)

(:if ! (group nosuchgroup AND false) :)
"! (expression)" works
(:ifend:)

"! (expression)" works

(:winter:(false OR date 2013-06-01..2013-11-14):)
{$:winter}

(false OR date 2013-06-01..2013-11-14)

(:if ! {$:winter}:)
It's summer
(:ifend:)

It's summer

(:if {$:winter}:)
It's winter
(:ifend:)

It's winter