bitset -- persistent set of unsigned integers
createa string representation of a bitset of the form "{2, 4}redefines Object.asString:
an empty bitset
test if the given bit is part of this bitset
get the highest bit in this bitset
alternative for has using []
compare two bitsets
union of two bitsets
set the given bit
monoid of bitset with infix ⋃ operation.
