Question : SQL for binary coupled elements?

I need a query for the many-to-many joined tables, below:

for every element of t in table1,
find every other element t, for which
they both are joined to the same element
q of table 2.

1: 2:

table 1 join table table 2 t i ----> ti ji ----> i q

Answer : SQL for binary coupled elements?

ti - join table, t = element t's id column, q = table q's id column

select C.name, D.name, E.name
from ti A inner join ti B on A.q=B.q and A.t <> B.t
inner join table1 C on C.t=A.t
inner join table1 D on D.t=B.t
inner join table2 E on E.q=B.q

This returns the name of each pair of elements C & D from table1 that are coupled (share the same link to) E