|| Extracted form the set1 content-dictionary
||	http://www.openmath.org/cd/set1.html

Symbol: cartesian_product APPLICATION		"set1:cartesian_product" 
Symbol: ×		OP_PROD			"set1:cartesian_product" 
Symbol: emptyset 	SYMBOL			"set1:emptyset"
Symbol: ∅		SYMBOL			"set1:emptyset"
Symbol: in		OP_PLUS			"set1:in"
Symbol: ∈		OP_PLUS			"set1:in"
Symbol: inter		OP_PROD			"set1:intersect"
Symbol: ∩		OP_PROD			"set1:intersect"
Symbol: map		APPLICATION		"set1:map"
Symbol: ->		OP_AND			"set1:map"
Symbol: →		OP_AND			"set1:map"
Symbol: not_in		OP_PLUS			"set1:notin"
Symbol: ¬∈		OP_PLUS			"set1:notin"
Symbol: ∉		OP_PLUS			"set1:notin"
Symbol: not_prsubset	OP_PLUS			"set1:notprsubset"
Symbol: ¬⊊		OP_PLUS			"set1:notprsubset"
Symbol: not_subset	OP_PLUS			"set1:notsubset"
Symbol: ⊄		OP_PLUS			"set1:notsubset"
Symbol: prsubset	OP_PLUS			"set1:prsubset"
Symbol: ⊊		OP_PLUS			"set1:prsubset"
|| currently no possibility of defining {}
Symbol: set		APPLICATION		"set1:set"
Symbol: setdiff		APPLICATION		"set1:setdiff"
Symbol: without		OP_PLUS			"set1:setdiff"
Symbol: \		OP_PLUS			"set1:setdiff"
Symbol: size 		APPLICATION		"set1:size"
Symbol: # 		APPLICATION		"set1:size"
Symbol: subset		OP_PLUS			"set1:subset"
Symbol: ⊂		OP_PLUS			"set1:subset"
Symbol: such_that	BINDING			"set1:suchthat"
Symbol: |		OP_BIND			"set1:suchthat"
Symbol: union		OP_PROD			"set1:union"
Symbol: ∪		OP_PROD			"set1:union"