description:
is-subset(one, two) returns |yes> if one is an exact subset of two, else |no>
where one and two are superpositions
examples:
is-subset(|b>, |a> + |b> + |c>)
|yes>
is-subset(8|c> + 13|d> + 0.2|a>, 0.3|a> + 2|b> + 9.7|c> + 13|d>)
|yes>
is-subset(|b> + |d>, |a> + |b> + |c>)
|no>
see also:
subset, mbr, is-mbr