$ printhi '#$Relation' isg ?
#$AssociativeRelation
#$CommutativeRelation
#$ELRelation
#$EvaluatableRelation
#$FixedArityRelation
#$Function-Denotational
#$FunctionalRelation
#$LogicalConnective
#$MacroRelation
#$MicrotheoryDesignatingRelation
#$ModalOperator
#$NLPredicate
#$PartiallyCommutativeRelation
#$ScopingRelation
#$TruthFunction
#$VariableArityRelation
