Venn diagram or names in a list

Hi Ian,

Better use some formatting to sort out issues with long formulas. Your initial one is

=IFERROR(
	INDEX(Table1[1],
		MATCH(0,
			COUNTIF(N$1:$N1,Table1[1])+
				IF(
					IF(COUNTIF(Table1[2],Table1[1])>0,1,0)+
					IF(COUNTIF(Table1[3],Table1[1])>0,1,0)=2,
					0,1
				),
		0)
	),
	""
)

In nested IF remove second IF with COUNTIF which indicates if elements from columns 3 and 1 are overlapped, and first IF here compare with 1. Thus formula for 1-2 will be

{=IFERROR(
	INDEX(Table1[1],
		MATCH(0,
			COUNTIF(N$1:$N1,Table1[1])+
				IF(
					IF(COUNTIF(Table1[2],Table1[1])>0,1,0)=1,
					0,1
				),
		0)
	),
	""
)}