Check if the token underlying a node is an unknown word.
returnedBoolean = variableType("$unknown"[, number])
returnedBoolean - type: bool
variableType - type: N
number - type: int
Returns 1 if the token is an unknown word and 0 if the token is a known word.
Requires a lookup( ) CODE Action prior to any use of this special variable.
WARNING: This special variable is not identical to the @PRE action, unknown(). $unknown will traverse down to the leafiest node it can find, in order to perform its check. The @PRE action only chains down if the [s] flag is present in the associated phrase element(s). Also, $unknown is not stopped by a [base] attribute in a node.
$exists, Special Variables