Wikipedia:WikiProject Interlanguage Links/induction

Definition

A 'potential induction' is determined using the SQL statement below:

SELECT sa.from_lang, sa.from_title, at.to_lang, at.to_title
FROM inter sa
INNER JOIN inter at ON at.from_lang = sa.to_lang AND at.from_title = sa.from_title AND at.to_lang != sa.from_lang
INNER JOIN inter sb ON sb.from_lang = sa.from_lang AND sb.from_title = sa.from_title AND sb.to_lang != sa.to_lang
INNER JOIN inter bt ON bt.from_lang = sb.to_lang AND bt.from_title = sb.from_title AND bt.to_lang = at.to_lang AND bt.to_title = at.to_title
LEFT OUTER JOIN inter st ON st.from_lang = sa.from_lang AND st.from_title = sa.from_title AND st.to_lang = at.to_lang
LEFT OUTER JOIN inter ts ON ts.from_lang = at.to_lang AND ts.from_title = at.to_title AND ts.to_lang = sa.from_lang AND ts.to_title = sa.from_title
WHERE st.from_title IS NULL
AND   ts.from_title IS NULL
AND   at.to_lang IN ( 'en','de','es','fr','it','nl','ja','pl','pt','sv' )
AND   sa.from_lang IN ( 'en','de','es','fr','it','nl','ja','pl','pt','sv' )

Note that this requires a 'corroborating' link that is A->B->C and A->D->C is required to imply that A->C. This seems to filter out most of the dubious links;

Results

The results below were generated in August 2007, from the most recently available database dump for each language.

Suggested reciprocal links
		from
		en	de	es	fr	it	nl	ja	pl	pt	sv
to	en		-	-	-	-	-	-	-	-	-
	de	X		-	-	-	-	-	-	-	-
	es	X	-		-	-	-	-	-	-	-
	fr	X	-	-		-	-	-	-	-	-
	it	X	-	-	-		-	-	-	-	-
	nl	X	-	-	-	-		-	-	-	-
	ja	X	-	-	-	-	-		-	-	-
	pl	X	-	-	-	-	-	-		-	-
	pt	X	-	-	-	-	-	-	-		-
	sv	X	-	-	-	-	-	-	-	-