ronnie sahlberg wrote:
The difference is the difference between the upside down A (==For ALL it
is true)
and the mirrored E (==there EXISTS at least one)
I.e.:
payload.packet.a_field != 1
means "there exists at least one instance of payload.packet.a_field in
the packet that has a value not equal to 1", not "all instances of
payload.packet.a_field in the packet have values not equal to 1", and
the negation of that is "all instances of payload.packet.a_field in the
packet have values equal to 1".
payload.packet.a_field == 1
means "there exists at least one instance of payload.packet.a_field with
a value equal to 1", which is not the opposite of "there exists at least
one instance of payload.packet.a_field in the packet that has a value
not equal to 1", i.e. it's not the opposite of
payload.packet.a_field != 1