begin %RECURSION%

VIEW Travel(x,y,t)
SELECT1 location1, location2, t2
FROM1 go
WHERE1 t1=0
SELECT2 tl.x, g.location2, g.t2
FROM2 Travel as tl, go as g
WHERE2 tl.y=g.location1, tl.t=g.t1
end %RECURSION%