Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
Function: setp (<a>) Returns true if and only if <a> is a Maxima set.

setp returns true for unsimplified sets (that is, sets with redundant members) as well as simplified sets.
setp is equivalent to the Maxima function setp(a) := not atom(a) and op(a) = set.
Examples:
(%i1) simp : false;
(%o1) false
(%i2) {a, a, a};
(%o2) {a, a, a}
(%i3) setp (%);
(%o3) true There are also some inexact matches for setp. Try ?? setp to see them.
(%o1) true (%i2)