Maxima Function
subsetp (a, b)
Returns true
if and only if the set a is a subset of b.
subsetp
complains if either a or b is not a literal set.
Examples:
(%i1) subsetp ({1, 2, 3}, {a, 1, b, 2, c, 3}); (%o1) true (%i2) subsetp ({a, 1, b, 2, c, 3}, {1, 2, 3}); (%o2) false