Sets

Z←L§R returns a vector consisting of the elements of L that are not in R.

L is a scalar or one-element vector.

R is a scalar or one-element vector.

Z is the vector result equivalent to (L~R),R~L.

Z←L⊆R returns a Boolean scalar indicating whether or not L is a subset of R.

L is a scalar or one-element vector.

R is a scalar or one-element vector.

Z is the Boolean scalar result equivalent to ∧/L∊R as well as R⊇L.

Z←L⊇R returns a Boolean scalar indicating whether or not L is a superset of R.

L is a scalar or one-element vector.

R is a scalar or one-element vector.

Z is the Boolean scalar result equivalent to ∧/R∊L as well as R⊆L.

These functions behave differently when invoked via the Multiset Operator which takes into account multiplicities.

For example,

      'miasma'§'sis'
mama
      'miasma'§⍦'sis' ⍝ Using the Multiset form
mamas
      'immiss'⊆'mississippi'
1
      'immiss'⊆⍦'mississippi' ⍝ Using the Multiset form
0                             ⍝ because the # m's doesn't match