The members of x1=simx1 (set) resemble one another in property x2=simx2.
simsa1 and simsa2 are merged into simxu1, by virtue of simxu's ability to take any 2-way relationship and make it into an n-way relationship (lujvopap.txt); cf. simsa, simxu, dunli, mintu, panra, ma'oste du.