algebra.difference(a, b)

Returns a set that represents the difference of sets A and B (A \ B), or returns if a difference exists.

algebra1 = new set.Algebra(set.props.boolean("completed"));
algebra2 = new set.Algebra();

// A has all of B
algebra1.difference( {} , {completed: true} ) //-> {completed: false}

// A has all of B, but we can't figure out how to create a set object
algebra2.difference( {} , {completed: true} ) //-> true

// A is totally inside B
algebra2.difference( {completed: true}, {} )  //-> false