    class
    	SUBSET_STRATEGY_TREE [G -> COMPARABLE]

    General
    	cluster: base
    	description:
    		"Strategies for calculating several features for subsets represented
    		by binary search trees. Contained items have to be COMPARABLE"

    Ancestors
    	SUBSET_STRATEGY* [G]

    Queries
    	disjoint (set1, set2: BINARY_SEARCH_TREE_SET [G]): BOOLEAN

    Commands
    	symdif (set1, set2: BINARY_SEARCH_TREE_SET [G])