convert number to cardinality selbri; x1 is a mass formed from a set x2 of n members, one or more of which is/are x3, measured relative to the set x4.
[x1 is a mass with N components x3 composing set x2; x2 is an n-tuple (x2 is completely specified) (= selmei for reordered places); x1 forms an n-some; x3 (not necessarily a complete enumeration) are among the members of x2); See also cmima, gunma, cmavo list moi.