core :: DisjointSet :: union_all
es
ENSURE: all_in_same_subset(cs)
all_in_same_subset(cs)
# Combine the subsets of all elements of `es` # ENSURE: `all_in_same_subset(cs)` fun union_all(es:Collection[E]) do if es.is_empty then return var f = es.first for e in es do union(e,f) end